Command Reference, Cisco IOS XE Gibraltar 16.10.x (Catalyst 9400 Switches)

clear ipv6 access-list

To reset the IPv6 access list match counters, use the clear ipv6 access-list command in privileged EXEC mode.

clear ipv6 access-list [access-list-name]

Syntax Description


`access-list-name`	(Optional) Name of the IPv6 access list for which to clear the match counters. Names cannot contain a space or quotation mark, or begin with a numeric.

Command Default

No reset is initiated.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

The clear ipv6 access-list command is similar to the clear ip access-list counters command, except that it is IPv6-specific.

The clear ipv6 access-list command used without the access-list-name argument resets the match counters for all IPv6 access lists configured on the router.

This command resets the IPv6 global ACL hardware counters.

Examples

The following example resets the match counters for the IPv6 access list named marketing:

Device# clear ipv6 access-list marketing

Related Commands


Command	Description
hardware statistics	Enables the collection of hardware statistics.
ipv6 access-list	Defines an IPv6 access list and enters IPv6 access list configuration mode.
show ipv6 access-list	Displays the contents of all current IPv6 access lists.

clear ipv6 dhcp

To clear IPv6 Dynamic Host Configuration Protocol (DHCP) information, use the clear ipv6 dhcp command in privileged EXEC mode:

clear ipv6 dhcp

Syntax Description

This command has no arguments or keywords.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

The clear ipv6 dhcp command deletes DHCP for IPv6 information.

Examples

The following example :


Device# clear ipv6 dhcp

clear ipv6 dhcp binding

To delete automatic client bindings from the Dynamic Host Configuration Protocol (DHCP) for IPv6 server binding table, use the clear ipv6 dhcp binding command in privileged EXEC mode.

clear ipv6 dhcp binding [ipv6-address] [vrf vrf-name]

Syntax Description


`ipv6-address`	(Optional) The address of a DHCP for IPv6 client. This argument must be in the form documented in RFC 2373 where the address is specified in hexadecimal using 16-bit values between colons.
vrf `vrf-name`	(Optional) Specifies a virtual routing and forwarding (VRF) configuration.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

The clear ipv6 dhcp binding command is used as a server function.

A binding table entry on the DHCP for IPv6 server is automatically:

Created whenever a prefix is delegated to a client from the configuration pool.
Updated when the client renews, rebinds, or confirms the prefix delegation.
Deleted when the client releases all the prefixes in the binding voluntarily, all prefixes’ valid lifetimes have expired, or an administrator runs the clear ipv6 dhcp binding command.

If the clear ipv6 dhcp binding command is used with the optional ipv6-address argument specified, only the binding for the specified client is deleted. If the clear ipv6 dhcp binding command is used without the ipv6-address argument, then all automatic client bindings are deleted from the DHCP for IPv6 binding table. If the optional vrf vrf-name keyword and argument combination is used, only the bindings for the specified VRF are cleared.

Examples

The following example deletes all automatic client bindings from the DHCP for IPv6 server binding table:


Device# clear ipv6 dhcp binding

Related Commands


Command	Description
show ipv6 dhcp binding	Displays automatic client bindings from the DHCP for IPv6 server binding table.

clear ipv6 dhcp client

To restart the Dynamic Host Configuration Protocol (DHCP) for IPv6 client on an interface, use the clear ipv6 dhcp client command in privileged EXEC mode.

clear ipv6 dhcp client interface-type interface-number

Syntax Description


`interface-type` `interface-number`	Interface type and number. For more information, use the question mark (? ) online help function.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

The clear ipv6 dhcp client command restarts the DHCP for IPv6 client on specified interface after first releasing and unconfiguring previously acquired prefixes and other configuration options (for example, Domain Name System [DNS] servers).

Examples

The following example restarts the DHCP for IPv6 client for Ethernet interface 1/0:


Device# clear ipv6 dhcp client Ethernet 1/0

Related Commands


Command	Description
show ipv6 dhcp interface	Displays DHCP for IPv6 interface information.

clear ipv6 dhcp conflict

To clear an address conflict from the Dynamic Host Configuration Protocol for IPv6 (DHCPv6) server database, use the clear ipv6 dhcp conflict command in privileged EXEC mode.

clear ipv6 dhcp conflict {* | ipv6-address | vrf vrf-name}

Syntax Description


*	Clears all address conflicts.
`ipv6-address`	Clears the host IPv6 address that contains the conflicting address.
vrf `vrf-name`	Specifies a virtual routing and forwarding (VRF) name.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

When you configure the DHCPv6 server to detect conflicts, it uses ping. The client uses neighbor discovery to detect clients and reports to the server through a DECLINE message. If an address conflict is detected, the address is removed from the pool, and the address is not assigned until the administrator removes the address from the conflict list.

If you use the asterisk (*) character as the address parameter, DHCP clears all conflicts.

If the vrf vrf-name keyword and argument are specified, only the address conflicts that belong to the specified VRF will be cleared.

Examples

The following example shows how to clear all address conflicts from the DHCPv6 server database:


Device# clear ipv6 dhcp conflict *

Related Commands


Command	Description
show ipv6 dhcp conflict	Displays address conflicts found by a DHCPv6 server when addresses are offered to the client.

clear ipv6 dhcp relay binding

To clear an IPv6 address or IPv6 prefix of a Dynamic Host Configuration Protocol (DHCP) for IPv6 relay binding, use the clear ipv6 dhcp relay binding command in privileged EXEC mode.

clear ipv6 dhcp relay binding {vrf vrf-name} {* | ipv6-address | ipv6-prefix}

clear ipv6 dhcp relay binding {vrf vrf-name} {* | ipv6-prefix}

Syntax Description


vrf `vrf-name`	Specifies a virtual routing and forwarding (VRF) configuration.
*	Clears all DHCPv6 relay bindings.
`ipv6-address`	DHCPv6 address.
`ipv6-prefix`	IPv6 prefix.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

The clear ipv6 dhcp relay binding command deletes a specific IPv6 address or IPv6 prefix of a DHCP for IPv6 relay binding. If no relay client is specified, no binding is deleted.

Examples

The following example shows how to clear the binding for a client with a specified IPv6 address:


Device# clear ipv6 dhcp relay binding 2001:0DB8:3333:4::5

The following example shows how to clear the binding for a client with the VRF name vrf1 and a specified prefix on a Cisco uBR10012 universal broadband device:

Device# clear ipv6 dhcp relay binding vrf vrf1 2001:DB8:0:1::/64

Related Commands


Command	Description
show ipv6 dhcp relay binding	Displays DHCPv6 IANA and DHCPv6 IAPD bindings on a relay agent.

clear ipv6 eigrp

To delete entries from Enhanced Interior Gateway Routing Protocol (EIGRP) for IPv6 routing tables, use the clear ipv6 eigrp command in privileged EXEC mode.

clear ipv6 eigrp [as-number] [neighbor [ipv6-address | interface-type interface-number]]

Syntax Description


`as-number`	(Optional) Autonomous system number.
neighbor	(Optional) Deletes neighbor router entries.
`ipv6-address`	(Optional) IPv6 address of a neighboring router.
`interface-type`	(Optional) The interface type of the neighbor router.
`interface-number`	(Optional) The interface number of the neighbor router.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

Use the clear ipv6 eigrp command without any arguments or keywords to clear all EIGRP for IPv6 routing table entries. Use the as-number argument to clear routing table entries on a specified process, and use the neighbor ipv6-address keyword and argument, or the interface-type interface-number argument, to remove a specific neighbor from the neighbor table.

Examples

The following example removes the neighbor whose IPv6 address is 3FEE:12E1:2AC1:EA32:


Device# clear ipv6 eigrp neighbor 3FEE:12E1:2AC1:EA32

clear ipv6 mfib counters

To reset all active Multicast Forwarding Information Base (MFIB) traffic counters, use the clear ipv6 mfib counters command in privileged EXEC mode.

clear ipv6 mfib [vrf vrf-name] counters [group-name | group-address [source-address | source-name]]

Syntax Description


vrf `vrf-name`	(Optional) Specifies a virtual routing and forwarding (VRF) configuration.
`group-name` \| `group-address`	(Optional) IPv6 address or name of the multicast group.
`source-address` \| `source-name`	(Optional) IPv6 address or name of the source.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

After you enable the clear ipv6 mfib counters command, you can determine if additional traffic is forwarded by using one of the following show commands that display traffic counters:

show ipv6 mfib
show ipv6 mfib active
show ipv6 mfib count
show ipv6 mfib interface
show ipv6 mfib summary

Examples

The following example clears and resets all MFIB traffic counters:


Device# clear ipv6 mfib counters

clear ipv6 mld counters

To clear the Multicast Listener Discovery (MLD) interface counters, use the clear ipv6 mld counters command in privileged EXEC mode.

clear ipv6 mld [vrf vrf-name] counters [interface-type]

Syntax Description


vrf `vrf-name`	(Optional) Specifies a virtual routing and forwarding (VRF) configuration.
`interface-type`	(Optional) Interface type. For more information, use the question mark (? ) online help function.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

Use the clear ipv6 mld counters command to clear the MLD counters, which keep track of the number of joins and leaves received. If you omit the optional interface-type argument, the clear ipv6 mld counters command clears the counters on all interfaces.

Examples

The following example clears the counters for Ethernet interface 1/0:


Device# clear ipv6 mld counters Ethernet1/0

Related Commands


Command	Description
show ipv6 mld interface	Displays multicast-related information about an interface.

clear ipv6 mld traffic

To reset the Multicast Listener Discovery (MLD) traffic counters, use the clear ipv6 mld traffic command in privileged EXEC mode.

clear ipv6 mld [vrf vrf-name] traffic

Syntax Description


vrf `vrf-name`	(Optional) Specifies a virtual routing and forwarding (VRF) configuration.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

Using the clear ipv6 mld traffic command will reset all MLD traffic counters.

Examples

The following example resets the MLD traffic counters:


Device# clear ipv6 mld traffic


Command	Description
show ipv6 mld traffic	Displays the MLD traffic counters.

clear ipv6 mtu

To clear the maximum transmission unit (MTU) cache of messages, use the clear ipv6 mtu command in privileged EXEC mode.

clear ipv6 mtu

Syntax Description

This command has no arguments or keywords.

Command Default

Messages are not cleared from the MTU cache.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

If a router is flooded with ICMPv6 toobig messages, the router is forced to create an unlimited number of entries in the MTU cache until all available memory is consumed. Use the clear ipv6 mtu command to clear messages from the MTU cache.

Examples

The following example clears the MTU cache of messages:


Device# clear ipv6 mtu

Related Commands


Command	Description
ipv6 flowset	Configures flow-label marking in 1280-byte or larger packets sent by the router.

clear ipv6 multicast aaa authorization

To clear authorization parameters that restrict user access to an IPv6 multicast network, use the clear ipv6 multicast aaa authorization command in privileged EXEC mode.

clear ipv6 multicast aaa authorization [interface-type interface-number]

Syntax Description


`interface-type` `interface-number`	Interface type and number. For more information, use the question mark (? ) online help function.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

Using the clear ipv6 multicast aaa authorization command without the optional interface-type and interface-number arguments will clear all authorization parameters on a network.

Examples

The following example clears all configured authorization parameters on an IPv6 network:


Device# clear ipv6 multicast aaa authorization FastEthernet 1/0

Related Commands


Command	Description
aaa authorization multicast default	Sets parameters that restrict user access to an IPv6 multicast network.

clear ipv6 nd destination

To clear IPv6 host-mode destination cache entries, use the clear ipv6 nd destination command in privileged EXEC mode.

clear ipv6 nd destination [vrf vrf-name]

Syntax Description


vrf `vrf-name`	(Optional) Specifies a virtual routing and forwarding (VRF) configuration.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

The clear ipv6 nd destination command clears IPv6 host-mode destination cache entries. If the vrf vrf-name keyword and argument pair is used, then only information about the specified VRF is cleared.

Examples

The following example shows how to clear IPv6 host-mode destination cache entries:

Device# clear ipv6 nd destination

Related Commands


Command	Description
ipv6 nd host mode strict	Enables the conformant, or strict, IPv6 host mode.

clear ipv6 nd on-link prefix

To clear on-link prefixes learned through router advertisements (RAs), use the clear ipv6 nd on-link prefix command in privileged EXEC mode.

clear ipv6 nd on-link prefix [vrf vrf-name]

Syntax Description


vrf `vrf-name`	(Optional) Specifies a virtual routing and forwarding (VRF) configuration.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

Use the clear ipv6 nd on-link prefix command to clear locally reachable IPv6 addresses (e.g., on-link prefixes) learned through RAs. If the vrf vrf-name keyword and argument pair is used, then only information about the specified VRF is cleared.

Examples

The following examples shows how to clear on-link prefixes learned through RAs:

Device# clear ipv6 nd on-link prefix

Related Commands


Command	Description
ipv6 nd host mode strict	Enables the conformant, or strict, IPv6 host mode.

clear ipv6 nd router

To clear neighbor discovery (ND) device entries learned through router advertisements (RAs), use the clear ipv6 nd router command in privileged EXEC mode.

clear ipv6 nd router [vrf vrf-name]

Syntax Description


vrf `vrf-name`	(Optional) Specifies a virtual routing and forwarding (VRF) configuration.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

Use the clear ipv6 nd router command to clear ND device entries learned through RAs. If the vrf vrf-name keyword and argument pair is used, then only information about the specified VRF is cleared.

Examples

The following example shows how to clear neighbor discovery ND device entries learned through RAs:


Device# clear ipv6 nd router

Related Commands


Command	Description
ipv6 nd host mode strict	Enables the conformant, or strict, IPv6 host mode.

clear ipv6 neighbors

To delete all entries in the IPv6 neighbor discovery cache, except static entries and ND cache entries on non-virtual routing and forwarding (VRF) interfaces, use the clear ipv6 neighbors command in privileged EXEC mode.

clear ipv6 neighbors [interface type number [ipv6 ipv6-address] | statistics | vrf table-name [ipv6-address | statistics]]

clear ipv6 neighbors

Syntax Description


interface `type` `number`	(Optional) Clears the IPv6 neighbor discovery cache in the specified interface.
ipv6 `ipv6-address`	(Optional) Clears the IPv6 neighbor discovery cache that matches the specified IPv6 address on the specified interface.
statistics	(Optional) Clears the IPv6 neighbor discovery entry cache.
vrf	(Optional) Clears entries for a virtual private network (VPN) routing or forwarding instance.
`table-name`	(Optional) Table name or identifier. The value range is from 0x0 to 0xFFFFFFFF (0 to 65535 in decimal).

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

The clear ipv6 neighbor command clears ND cache entries. If the command is issued without the vrf keyword, then the command clears ND cache entries on interfaces associated with the default routing table (e.g., those interfaces that do not have a vrf forwarding statement). If the command is issued with the vrf keyword, then it clears ND cache entries on interfaces associated with the specified VRF.

Examples

The following example deletes all entries, except static entries and ND cache entries on non-VRF interfaces, in the neighbor discovery cache:


Device# clear ipv6 neighbors

The following example clears all IPv6 neighbor discovery cache entries, except static entries and ND cache entries on non-VRF interfaces, on Ethernet interface 0/0:


Device# clear ipv6 neighbors interface Ethernet 0/0

The following example clears a neighbor discovery cache entry for 2001:0DB8:1::1 on Ethernet interface 0/0:


Device# clear ipv6 neighbors interface Ethernet0/0 ipv6 2001:0DB8:1::1

In the following example, interface Ethernet 0/0 is associated with the VRF named red. Interfaces Ethernet 1/0 and Ethernet 2/0 are associated with the default routing table (because they are not associated with a VRF). Therefore, the clear ipv6 neighbor command will clear ND cache entries on interfaces Ethernet 1/0 and Ethernet 2/0 only. In order to clear ND cache entries on interface Ethernet 0/0, the user must issue the clear ipv6 neighbor vrf red command.

interface ethernet0/0
  vrf forward red
  ipv6 address 2001:db8:1::1/64

interface ethernet1/0
   ipv6 address 2001:db8:2::1/64

interface ethernet2/0
   ipv6 address 2001:db8:3::1/64

Related Commands


Command	Description
ipv6 neighbor	Configures a static entry in the IPv6 neighbor discovery cache.
show ipv6 neighbors	Displays IPv6 neighbor discovery cache information.

clear ipv6 nhrp

To clear all dynamic entries from the Next Hop Resolution Protocol (NHRP) cache, use the clear ipv6 nhrp command in privileged EXEC mode.

clear ipv6 nhrp [ipv6-address | counters]

Syntax Description


`ipv6-address`	(Optional) The IPv6 network to delete.
counters	(Optional) Specifies NHRP counters to delete.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

This command does not clear any static (configured) IPv6-to-nonbroadcast multiaccess (NBMA) address mappings from the NHRP cache.

Examples

The following example shows how to clear all dynamic entries from the NHRP cache for the interface:


Device# clear ipv6 nhrp

Related Commands


Command	Description
show ipv6 nhrp	Displays the NHRP cache.

clear ipv6 ospf

To clear the Open Shortest Path First (OSPF) state based on the OSPF routing process ID, use the cl ear ipv6 ospf command in privileged EXEC mode.

clear ipv6 ospf [process-id] {process | force-spf | redistribution}

Syntax Description


`process-id`	(Optional) Internal identification. It is locally assigned and can be any positive integer. The number used here is the number assigned administratively when enabling the OSPF routing process.
process	Restarts the OSPF process.
force-spf	Starts the shortest path first (SPF) algorithm without first clearing the OSPF database.
redistribution	Clears OSPF route redistribution.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

When the process keyword is used with the clear ipv6 ospf command, the OSPF database is cleared and repopulated, and then the shortest path first (SPF) algorithm is performed. When the force-spf keyword is used with the clear ipv6 ospf command, the OSPF database is not cleared before the SPF algorithm is performed.

Use the process-id option to clear only one OSPF process. If the process-id option is not specified, all OSPF processes are cleared.

Examples

The following example starts the SPF algorithm without clearing the OSPF database:


Device# clear ipv6 ospf force-spf

clear ipv6 ospf counters

To clear the Open Shortest Path First (OSPF) state based on the OSPF routing process ID, use the cl ear ipv6 ospf command in privileged EXEC mode.

clear ipv6 ospf [process-id] counters [neighbor [neighbor-interface | neighbor-id]]

Syntax Description


`process-id`	(Optional) Internal identification. It is locally assigned and can be any positive integer. The number used here is the number assigned administratively when enabling the OSPF routing process.
neighbor	(Optional) Neighbor statistics per interface or neighbor ID.
`neighbor-interface`	(Optional) Neighbor interface.
`neighbor-id`	(Optional) IPv6 or IP address of the neighbor.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

Use the neighbor neighbor-interface option to clear counters for all neighbors on a specified interface. If the neighbor neighbor-interface option is not used, all OSPF counters are cleared.

Use the neighbor neighbor-id option to clear counters at a specified neighbor. If the neighbor neighbor-id option is not used, all OSPF counters are cleared.

Examples

The following example provides detailed information on a neighbor router:


Device# show ipv6 ospf neighbor detail
 Neighbor 10.0.0.1
    In the area 1 via interface Serial19/0
    Neighbor:interface-id 21, link-local address FE80::A8BB:CCFF:FE00:6F00
    Neighbor priority is 1, State is FULL, 6 state changes
    Options is 0x194AE05
    Dead timer due in 00:00:37
    Neighbor is up for 00:00:15
    Index 1/1/1, retransmission queue length 0, number of retransmission 1
    First 0x0(0)/0x0(0)/0x0(0) Next 0x0(0)/0x0(0)/0x0(0)
    Last retransmission scan length is 1, maximum is 1
    Last retransmission scan time is 0 msec, maximum is 0 msec

The following example clears all neighbors on the specified interface:


Device# clear ipv6 ospf counters neighbor s19/0

The following example now shows that there have been 0 state changes since the clear ipv6 ospf counters neighbor s19/0 command was used:


Device# show ipv6 ospf neighbor detail
 Neighbor 10.0.0.1
    In the area 1 via interface Serial19/0
    Neighbor:interface-id 21, link-local address FE80::A8BB:CCFF:FE00:6F00
    Neighbor priority is 1, State is FULL, 0 state changes
    Options is 0x194AE05
    Dead timer due in 00:00:39
    Neighbor is up for 00:00:43
    Index 1/1/1, retransmission queue length 0, number of retransmission 1
    First 0x0(0)/0x0(0)/0x0(0) Next 0x0(0)/0x0(0)/0x0(0)
    Last retransmission scan length is 1, maximum is 1
    Last retransmission scan time is 0 msec, maximum is 0 msec

Related Commands


Command	Description
show ipv6 ospf neighbor	Displays OSPF neighbor information on a per-interface basis.

clear ipv6 ospf events

To clear the Open Shortest Path First (OSPF) for IPv6 event log content based on the OSPF routing process ID, use the cl ear ipv6 ospf events command in privileged EXEC mode.

clear ipv6 ospf [process-id] events

Syntax Description


`process-id`	(Optional) Internal identification. It is locally assigned and can be any positive integer. The number used here is the number assigned administratively when enabling the OSPF routing process.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

Use the optional process-id argument to clear the IPv6 event log content of a specified OSPF routing process. If the process-id argument is not used, all event log content is cleared.

Examples

The following example enables the clearing of OSPF for IPv6 event log content for routing process 1:


Device# clear ipv6 ospf 1 events

clear ipv6 pim reset

To delete all entries from the topology table and reset the Multicast Routing Information Base (MRIB) connection, use the clear ipv6 pim reset command in privileged EXEC mode.

clear ipv6 pim [vrf vrf-name] reset

Syntax Description


vrf `vrf-name`	(Optional) Specifies a virtual routing and forwarding (VRF) configuration.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

Using the clear ipv6 pim reset command breaks the PIM-MRIB connection, clears the topology table, and then reestablishes the PIM-MRIB connection. This procedure forces MRIB resynchronization.

Caution

Use the clear ipv6 pim reset command with caution, as it clears all PIM protocol information from the PIM topology table. Use of the clear ipv6 pim reset command should be reserved for situations where PIM and MRIB communication are malfunctioning.

Examples

The following example deletes all entries from the topology table and resets the MRIB connection:


Device# clear ipv6 pim reset

clear ipv6 pim topology

To clear the Protocol Independent Multicast (PIM) topology table, use the clear ipv6 pim topology command in privileged EXEC mode.

clear ipv6 pim [vrf vrf-name] topology [group-name | group-address]

Syntax Description


vrf `vrf-name`	(Optional) Specifies a virtual routing and forwarding (VRF) configuration.
`group-name` \| `group-address`	(Optional) IPv6 address or name of the multicast group.

Command Default

When the command is used with no arguments, all group entries located in the PIM topology table are cleared of PIM protocol information.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

This command clears PIM protocol information from all group entries located in the PIM topology table. Information obtained from the MRIB table is retained. If a multicast group is specified, only those group entries are cleared.

Examples

The following example clears all group entries located in the PIM topology table:


Device# clear ipv6 pim topology

clear ipv6 pim traffic

To clear the Protocol Independent Multicast (PIM) traffic counters, use the clear ipv6 pim traffic command in privileged EXEC mode.

clear ipv6 pim [vrf vrf-name] traffic

Syntax Description


vrf `vrf-name`	(Optional) Specifies a virtual routing and forwarding (VRF) configuration.

Command Default

When the command is used with no arguments, all traffic counters are cleared.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

This command clears PIM traffic counters. If the vrf vrf-name keyword and argument are used, only those counters are cleared.

Examples

The following example clears all PIM traffic counter:


Device# clear ipv6 pim traffic

clear ipv6 prefix-list

To reset the hit count of the IPv6 prefix list entries, use the clear ipv6 prefix-list command in privileged EXEC mode.

clear ipv6 prefix-list [prefix-list-name] [ipv6-prefix/prefix-length]

Syntax Description


`prefix-list-name`	(Optional) The name of the prefix list from which the hit count is to be cleared.
`ipv6-prefix`	(Optional) The IPv6 network from which the hit count is to be cleared. This argument must be in the form documented in RFC 2373 where the address is specified in hexadecimal using 16-bit values between colons.
/ `prefix-length`	(Optional) The length of the IPv6 prefix. A decimal value that indicates how many of the high-order contiguous bits of the address comprise the prefix (the network portion of the address). A slash mark must precede the decimal value.

Command Default

The hit count is automatically cleared for all IPv6 prefix lists.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

The clear ipv6 prefix-list command is similar to the clear ip prefix-list command, except that it is IPv6-specific.

The hit count is a value indicating the number of matches to a specific prefix list entry.

Examples

The following example clears the hit count from the prefix list entries for the prefix list named first_list that match the network mask 2001:0DB8::/ 35.


Device# clear ipv6 prefix-list first_list 2001:0DB8::/35

Related Commands


Command	Description
ipv6 prefix-list	Creates an entry in an IPv6 prefix list.
ipv6 prefix-list sequence-number	Enables the generation of sequence numbers for entries in an IPv6 prefix list.
show ipv6 prefix-list	Displays information about an IPv6 prefix list or prefix list entries.

clear ipv6 rip

To delete routes from the IPv6 Routing Information Protocol (RIP) routing table, use the clear ipv6 rip command in privileged EXEC mode.

clear ipv6 rip [name] [vrf vrf-name]

clear ipv6 rip [name]

Syntax Description


`name`	(Optional) Name of an IPv6 RIP process.
vrf `vrf-name`	(Optional) Clears information about the specified Virtual Routing and Forwarding (VRF) instance.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

When the name argument is specified, only routes for the specified IPv6 RIP process are deleted from the IPv6 RIP routing table. If no name argument is specified, all IPv6 RIP routes are deleted.

Use the show ipv6 rip command to display IPv6 RIP routes.

Use the clear ipv6 rip name vrf vrf-name command to delete the specified VRF instances for the specified IPv6 RIP process.

Examples

The following example deletes all the IPv6 routes for the RIP process called one:


Device# clear ipv6 rip one

The following example deletes the IPv6 VRF instance, called vrf1 for the RIP process, called one:


Device# clear ipv6 rip one vrf vrf1

*Mar 15 12:36:17.022: RIPng: Deleting 2001:DB8::/32
*Mar 15 12:36:17.022: [Exec]IPv6RT[vrf1]: rip <name>, Delete all next-hops for 2001:DB8::1
*Mar 15 12:36:17.022: [Exec]IPv6RT[vrf1]: rip <name>, Delete 2001:DB8::1 from table
*Mar 15 12:36:17.022: [IPv6 RIB Event Handler]IPv6RT[<red>]: Event: 2001:DB8::1, Del, owner rip, previous None

Related Commands


Command	Description
debug ipv6 rip	Displays the current contents of the IPv6 RIP routing table.
ipv6 rip vrf-mode enable	Enables VRF-aware support for IPv6 RIP.
show ipv6 rip	Displays the current content of the IPv6 RIP routing table.

clear ipv6 route

To delete routes from the IPv6 routing table, use the clear ipv6 route command in privileged EXEC mode.

{clear ipv6 route {ipv6-address | ipv6-prefix/prefix-length} | *}

Syntax Description


`ipv6-address`	The address of the IPv6 network to delete from the table. This argument must be in the form documented in RFC 2373 where the address is specified in hexadecimal using 16-bit values between colons.
`ipv6-prefix`	The IPv6 network number to delete from the table. This argument must be in the form documented in RFC 2373 where the address is specified in hexadecimal using 16-bit values between colons.
/ `prefix-length`	The length of the IPv6 prefix. A decimal value that indicates how many of the high-order contiguous bits of the address comprise the prefix (the network portion of the address). A slash mark must precede the decimal value.
*	Clears all IPv6 routes.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

The clear ipv6 route command is similar to the clear ip route command, except that it is IPv6-specific.

When the ipv6-address or ipv6-prefix/ prefix- length argument is specified, only that route is deleted from the IPv6 routing table. When the * keyword is specified, all routes are deleted from the routing table (the per-destination maximum transmission unit [MTU] cache is also cleared).

Examples

The following example deletes the IPv6 network 2001:0DB8::/ 35:


Device# clear ipv6 route 2001:0DB8::/35

Related Commands


Command	Description
ipv6 route	Establishes static IPv6 routes.
show ipv6 route	Displays the current contents of the IPv6 routing table.

clear ipv6 spd

To clear the most recent Selective Packet Discard (SPD) state transition, use the clear ipv6 spd command in privileged EXEC mode.

clear ipv6 spd

Syntax Description

This command has no arguments or keywords.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

The clear ipv6 spd command removes the most recent SPD state transition and any trend historical data.

Examples

The following example shows how to clear the most recent SPD state transition:


Device# clear ipv6 spd

clear ipv6 traffic

To reset IPv6 traffic counters, use the clear ipv6 traffic command in privileged EXEC mode.

clear ipv6 traffic [interface-type interface-number]

Syntax Description


`interface-type` `interface-number`	Interface type and number. For more information, use the question mark (? ) online help function.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

Using this command resets the counters in the output from the show ipv6 traffic command.

Examples

The following example resets the IPv6 traffic counters. The output from the show ipv6 traffic command shows that the counters are reset:


Device# clear ipv6 traffic
Device# show ipv6 traffic
IPv6 statistics:
  Rcvd:  1 total, 1 local destination
         0 source-routed, 0 truncated
         0 format errors, 0 hop count exceeded
         0 bad header, 0 unknown option, 0 bad source
         0 unknown protocol, 0 not a router
         0 fragments, 0 total reassembled
         0 reassembly timeouts, 0 reassembly failures
  Sent:  1 generated, 0 forwarded
         0 fragmented into 0 fragments, 0 failed
         0 encapsulation failed, 0 no route, 0 too big
  Mcast: 0 received, 0 sent
ICMP statistics:
  Rcvd: 1 input, 0 checksum errors, 0 too short
        0 unknown info type, 0 unknown error type
        unreach: 0 routing, 0 admin, 0 neighbor, 0 address, 0 port
        parameter: 0 error, 0 header, 0 option
        0 hopcount expired, 0 reassembly timeout,0 too big
        0 echo request, 0 echo reply
        0 group query, 0 group report, 0 group reduce
        0 router solicit, 0 router advert, 0 redirects
        0 neighbor solicit, 1 neighbor advert
Sent: 1 output
        unreach: 0 routing, 0 admin, 0 neighbor, 0 address, 0 port
        parameter: 0 error, 0 header, 0 option
        0 hopcount expired, 0 reassembly timeout,0 too big
        0 echo request, 0 echo reply
        0 group query, 0 group report, 0 group reduce
        0 router solicit, 0 router advert, 0 redirects
        0 neighbor solicit, 1 neighbor advert
UDP statistics:
  Rcvd: 0 input, 0 checksum errors, 0 length errors
        0 no port, 0 dropped
  Sent: 0 output
TCP statistics:
  Rcvd: 0 input, 0 checksum errors
  Sent: 0 output, 0 retransmitted

Related Commands


Command	Description
show ipv6 traffic	Displays IPv6 traffic statistics.

ipv6 access-list

To define an IPv6 access list and to place the device in IPv6 access list configuration mode, use the ipv6 access-list command in global configuration mode. To remove the access list, use the no form of this command.

ipv6 access-list access-list-name

no ipv6 access-list access-list-name

Syntax Description


`access-list-name`	Name of the IPv6 access list. Names cannot contain a space or quotation mark, or begin with a numeric.

Command Default

No IPv6 access list is defined.

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

The ipv6 access-list command is similar to the ip access-list command, except that it is IPv6-specific.

The standard IPv6 ACL functionality supports --in addition to traffic filtering based on source and destination addresses--filtering of traffic based on IPv6 option headers and optional, upper-layer protocol type information for finer granularity of control (functionality similar to extended ACLs in IPv4). IPv6 ACLs are defined by using the ipv6 access-list command in global configuration mode and their permit and deny conditions are set by using the deny and permit commands in IPv6 access list configuration mode. Configuring the ipv6 access-list command places the device in IPv6 access list configuration mode--the device prompt changes to Device(config-ipv6-acl)#. From IPv6 access list configuration mode, permit and deny conditions can be set for the defined IPv6 ACL.

Note

IPv6 ACLs are defined by a unique name (IPv6 does not support numbered ACLs). An IPv4 ACL and an IPv6 ACL cannot share the same name.

For backward compatibility, the ipv6 access-list command with the deny and permit keywords in global configuration mode is still supported; however, an IPv6 ACL defined with deny and permit conditions in global configuration mode is translated to IPv6 access list configuration mode.

Refer to the deny (IPv6) and permit (IPv6) commands for more information on filtering IPv6 traffic based on IPv6 option headers and optional, upper-layer protocol type information. See the "Examples" section for an example of a translated IPv6 ACL configuration.

Note

Every IPv6 ACL has implicit permit icmp any any nd-na , permit icmp any any nd-ns , and deny ipv6 any any statements as its last match conditions. (The former two match conditions allow for ICMPv6 neighbor discovery.) An IPv6 ACL must contain at least one entry for the implicit deny ipv6 any any statement to take effect. The IPv6 neighbor discovery process makes use of the IPv6 network layer service; therefore, by default, IPv6 ACLs implicitly allow IPv6 neighbor discovery packets to be sent and received on an interface. In IPv4, the Address Resolution Protocol (ARP), which is equivalent to the IPv6 neighbor discovery process, makes use of a separate data link layer protocol; therefore, by default, IPv4 ACLs implicitly allow ARP packets to be sent and received on an interface.

Note

IPv6 prefix lists, not access lists, should be used for filtering routing protocol prefixes.

Use the ipv6 traffic-filter interface configuration command with the access-list-name argument to apply an IPv6 ACL to an IPv6 interface. Use the ipv6 access-class line configuration command with the access-list-name argument to apply an IPv6 ACL to incoming and outgoing IPv6 virtual terminal connections to and from the device.

Note

An IPv6 ACL applied to an interface with the ipv6 traffic-filter command filters traffic that is forwarded, not originated, by the device.

Note

When using this command to modify an ACL that is already associated with a bootstrap router (BSR) candidate rendezvous point (RP) (see the ipv6 pim bsr candidate rp command) or a static RP (see the ipv6 pim rp-address command), any added address ranges that overlap the PIM SSM group address range (FF3x::/96) are ignored. A warning message is generated and the overlapping address ranges are added to the ACL, but they have no effect on the operation of the configured BSR candidate RP or static RP commands.

Duplicate remark statements can no longer be configured from the IPv6 access control list. Because each remark statement is a separate entity, each one is required to be unique.

Examples

The following example is from a device running Cisco IOS Release 12.0(23)S or later releases. The example configures the IPv6 ACL list named list1 and places the device in IPv6 access list configuration mode.


Device(config)# ipv6 access-list list1
Device(config-ipv6-acl)#

The following example is from a device running Cisco IOS Release 12.2(2)T or later releases, 12.0(21)ST, or 12.0(22)S. The example configures the IPv6 ACL named list2 and applies the ACL to outbound traffic on Ethernet interface 0. Specifically, the first ACL entry keeps all packets from the network FEC0:0:0:2::/64 (packets that have the site-local prefix FEC0:0:0:2 as the first 64 bits of their source IPv6 address) from exiting out of Ethernet interface 0. The second entry in the ACL permits all other traffic to exit out of Ethernet interface 0. The second entry is necessary because an implicit deny all condition is at the end of each IPv6 ACL.


Device(config)# ipv6 access-list list2 deny FEC0:0:0:2::/64 any
Device(config)# ipv6 access-list list2 permit any any
Device(config)# interface ethernet 0
Device(config-if)# ipv6 traffic-filter list2 out

If the same configuration was entered on a device running Cisco IOS Release 12.0(23)S or later releases, the configuration would be translated into IPv6 access list configuration mode as follows:


ipv6 access-list list2 
  deny FEC0:0:0:2::/64 any
  permit ipv6 any any
interface ethernet 0
 ipv6 traffic-filter list2 out

Note

IPv6 is automatically configured as the protocol type in permit any any and deny any any statements that are translated from global configuration mode to IPv6 access list configuration mode.

Note

IPv6 ACLs defined on a device running Cisco IOS Release 12.2(2)T or later releases, 12.0(21)ST, or 12.0(22)S that rely on the implicit deny condition or specify a deny any any statement to filter traffic should contain permit statements for link-local and multicast addresses to avoid the filtering of protocol packets (for example, packets associated with the neighbor discovery protocol). Additionally, IPv6 ACLs that use deny statements to filter traffic should use a permit any any statement as the last statement in the list.

Note

An IPv6 device will not forward to another network an IPv6 packet that has a link-local address as either its source or destination address (and the source interface for the packet is different from the destination interface for the packet).

Related Commands


Command	Description
deny (IPv6)	Sets deny conditions for an IPv6 access list.
ipv6 access-class	Filters incoming and outgoing connections to and from the device based on an IPv6 access list.
ipv6 pim bsr candidate rp	Configures the candidate RP to send PIM RP advertisements to the BSR.
ipv6 pim rp-address	Configure the address of a PIM RP for a particular group range.
ipv6 traffic-filter	Filters incoming or outgoing IPv6 traffic on an interface.
permit (IPv6)	Sets permit conditions for an IPv6 access list.
show ipv6 access-list	Displays the contents of all current IPv6 access lists.

ipv6 cef

To enable Cisco Express Forwarding for IPv6, use the ipv6 cef command in global configuration mode. To disable Cisco Express Forwarding for IPv6, use the no form of this command.

ipv6 cef

no ipv6 cef

Syntax Description

This command has no arguments or keywords.

Command Default

Cisco Express Forwarding for IPv6 is disabled by default.

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

The ipv6 cef command is similar to the ip cef command, except that it is IPv6-specific.

The ipv6 cef command is not available on the Cisco 12000 series Internet routers because this distributed platform operates only in distributed Cisco Express Forwarding for IPv6 mode.

Note

The ipv6 cef command is not supported in interface configuration mode.

Note

Some distributed architecture platforms support both Cisco Express Forwarding for IPv6 and distributed Cisco Express Forwarding for IPv6. When Cisco Express Forwarding for IPv6 is configured on distributed platforms, Cisco Express Forwarding switching is performed by the Route Processor (RP).

Note

You must enable Cisco Express Forwarding for IPv4 by using the ip cef global configuration command before enabling Cisco Express Forwarding for IPv6 by using the ipv6 cef global configuration command.

Cisco Express Forwarding for IPv6 is advanced Layer 3 IP switching technology that functions the same and offer the same benefits as Cisco Express Forwarding for IPv4. Cisco Express Forwarding for IPv6 optimizes network performance and scalability for networks with dynamic, topologically dispersed traffic patterns, such as those associated with web-based applications and interactive sessions.

Examples

The following example enables standard Cisco Express Forwarding for IPv4 operation and then standard Cisco Express Forwarding for IPv6 operation globally on the Device.


Device(config)# ip cef
Device(config)# ipv6 cef

Related Commands


Command	Description
ip route-cache	Controls the use of high-speed switching caches for IP routing.
ipv6 cef accounting	Enables Cisco Express Forwarding for IPv6 and distributed Cisco Express Forwarding for IPv6 network accounting.
ipv6 cef distributed	Enables distributed Cisco Express Forwarding for IPv6.
show cef	Displays which packets the line cards dropped or displays which packets were not express-forwarded.
show ipv6 cef	Displays entries in the IPv6 FIB.

ipv6 cef accounting

To enable Cisco Express Forwarding for IPv6 and distributed Cisco Express Forwarding for IPv6 network accounting, use the ipv6 cef accounting command in global configuration mode or interface configuration mode. To disable Cisco Express Forwarding for IPv6 network accounting, use the no form of this command.

ipv6 cef accounting accounting-types

no ipv6 cef accounting accounting-types

Specific Cisco Express Forwarding Accounting Information Through Interface Configuration Mode

ipv6 cef accounting non-recursive {external | internal}

no ipv6 cef accounting non-recursive {external | internal}

Syntax Description


`accounting-types`	The `accounting-types` argument must be replaced with at least one of the following keywords. Optionally, you can follow this keyword by any or all of the other keywords, but you can use each keyword only once. load-balance-hash --Enables load balancing hash bucket counters. non-recursive --Enables accounting through nonrecursive prefixes. per-prefix --Enables express forwarding of the collection of the number of packets and bytes to a destination (or prefix). prefix-length --Enables accounting through prefix length.
non-recursive	Enables accounting through nonrecursive prefixes. This keyword is optional when used in global configuration mode after another keyword is entered. See the `accounting-types` argument.
external	Counts input traffic in the nonrecursive external bin.
internal	Counts input traffic in the nonrecursive internal bin.

Command Default

Cisco Express Forwarding for IPv6 network accounting is disabled by default.

Command Modes

Global configuration (config)

Interface configuration (config-if)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

The ipv6 cef accounting command is similar to the ip cef accounting command, except that it is IPv6-specific.

Configuring Cisco Express Forwarding for IPv6 network accounting enables you to collect statistics on Cisco Express Forwarding for IPv6 traffic patterns in your network.

When you enable network accounting for Cisco Express Forwarding for IPv6 by using the ipv6 cef accounting command in global configuration mode, accounting information is collected at the Route Processor (RP) when Cisco Express Forwarding for IPv6 mode is enabled and at the line cards when distributed Cisco Express Forwarding for IPv6 mode is enabled. You can then display the collected accounting information using the show ipv6 cef EXEC command.

For prefixes with directly connected next hops, the non-recursive keyword enables express forwarding of the collection of packets and bytes through a prefix. This keyword is optional when this command is used in global configuration mode after you enter another keyword on the ipv6 cef accounting command.

This command in interface configuration mode must be used in conjunction with the global configuration command. The interface configuration command allows a user to specify two different bins (internal or external) for the accumulation of statistics. The internal bin is used by default. The statistics are displayed through the show ipv6 cef detail command.

Per-destination load balancing uses a series of 16 hash buckets into which the set of available paths are distributed. A hash function operating on certain properties of the packet is applied to select a bucket that contains a path to use. The source and destination IP addresses are the properties used to select the bucket for per-destination load balancing. Use the load-balance-hash keyword with the ipv6 cef accounting command to enable per-hash-bucket counters. Enter the show ipv6 cef prefix internal command to display the per-hash-bucket counters.

Examples

The following example enables the collection of Cisco Express Forwarding for IPv6 accounting information for prefixes with directly connected next hops:

Device(config)# ipv6 cef accounting non-recursive

Related Commands


Command	Description
ip cef accounting	Enable Cisco Express Forwarding network accounting (for IPv4).
show cef	Displays information about packets forwarded by Cisco Express Forwarding.
show ipv6 cef	Displays entries in the IPv6 FIB.

ipv6 cef distributed

To enable distributed Cisco Express Forwarding for IPv6, use the ipv6 cef distributed command in global configuration mode. To disable Cisco Express Forwarding for IPv6, use the no form of this command.

ipv6 cef distributed

no ipv6 cef distributed

Syntax Description

This command has no arguments or keywords.

Command Default

Distributed Cisco Express Forwarding for IPv6 is disabled by default.

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

The ipv6 cef distributed command is similar to the ip cef distributed command, except that it is IPv6-specific.

Enabling distributed Cisco Express Forwarding for IPv6 globally on the router by using the ipv6 cef distributed in global configuration mode distributes the Cisco Express Forwarding processing of IPv6 packets from the Route Processor (RP) to the line cards of distributed architecture platforms.

Note

To forward distributed Cisco Express Forwarding for IPv6 traffic on the router, configure the forwarding of IPv6 unicast datagrams globally on your router by using the ipv6 unicast-routing global configuration command, and configure an IPv6 address and IPv6 processing on an interface by using the ipv6 address interface configuration command.

Note

You must enable distributed Cisco Express Forwarding for IPv4 by using the ip cef distributed global configuration command before enabling distributed Cisco Express Forwarding for IPv6 by using the ipv6 cef distributed global configuration command.

Cisco Express Forwarding is advanced Layer 3 IP switching technology. Cisco Express Forwarding optimizes network performance and scalability for networks with dynamic, topologically dispersed traffic patterns, such as those associated with web-based applications and interactive sessions.

Examples

The following example enables distributed Cisco Express Forwarding for IPv6 operation:


Device(config)# ipv6 cef distributed

Related Commands


Command	Description
ip route-cache	Controls the use of high-speed switching caches for IP routing.
show ipv6 cef	Displays entries in the IPv6 FIB.

ipv6 cef load-sharing algorithm

To select a Cisco Express Forwarding load-balancing algorithm for IPv6, use the ipv6 cef load-sharing algorithm command in global configuration mode. To return to the default universal load-balancing algorithm, use the no form of this command.

ipv6 cef load-sharing algorithm {original | universal [id] }

no ipv6 cef load-sharing algorithm

Syntax Description


original	Sets the load-balancing algorithm to the original algorithm based on a source and destination hash.
universal	Sets the load-balancing algorithm to the universal algorithm that uses a source and destination and an ID hash.
`id`	(Optional) Fixed identifier in hexadecimal format.

Command Default

The universal load-balancing algorithm is selected by default. If you do not configure the fixed identifier for a load-balancing algorithm, the router automatically generates a unique ID.

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

The ipv6 cef load-sharing algorithm command is similar to the ip cef load-sharing algorithm command, except that it is IPv6-specific.

When the Cisco Express Forwarding for IPv6 load-balancing algorithm is set to universal mode, each device on the network can make a different load-sharing decision for each source-destination address pair.

Examples

The following example shows how to enable the Cisco Express Forwarding original load-balancing algorithm for IPv6:


Device(config)# ipv6 cef load-sharing algorithm original

Related Commands


Command	Description
ip cef load-sharing algorithm	Selects a Cisco Express Forwarding load-balancing algorithm (for IPv4).

ipv6 cef optimize neighbor resolution

To configure address resolution optimization from Cisco Express Forwarding for IPv6 for directly connected neighbors, use the ipv6 cef optimize neighbor resolution command in global configuration mode. To disable address resolution optimization from Cisco Express Forwarding for IPv6 for directly connected neighbors, use the no form of this command.

ipv6 cef optimize neighbor resolution

no ipv6 cef optimize neighbor resolution

Syntax Description

This command has no arguments or keywords.

Command Default

If this command is not configured, Cisco Express Forwarding for IPv6 does not optimize the address resolution of directly connected neighbors.

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

The ipv6 cef optimize neighbor resolution command is very similar to the ip cef optimize neighbor resolution command, except that it is IPv6-specific.

Use this command to trigger Layer 2 address resolution of neighbors directly from Cisco Express Forwarding for IPv6.

Examples

The following example shows how to optimize address resolution from Cisco Express Forwarding for IPv6 for directly connected neighbors:


Device(config)# ipv6 cef optimize neighbor resolution

Related Commands


Command	Description
ip cef optimize neighbor resolution	Configures address resolution optimization from Cisco Express Forwarding for IPv4 for directly connected neighbors.

ipv6 destination-guard policy

To define a destination guard policy, use the ipv6 destination-guard policy command in global configuration mode. To remove the destination guard policy, use the no form of this command.

ipv6 destination-guard policy [policy-name]

no ipv6 destination-guard policy [policy-name]

Syntax Description


`policy-name`	(Optional) Name of the destination guard policy.

Command Default

No destination guard policy is defined.

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

This command enters destination-guard configuration mode. The destination guard policies can be used to filter IPv6 traffic based on the destination address to block data traffic from an unknown source.

Examples

The following example shows how to define the name of a destination guard policy:


Device(config)#ipv6 destination-guard policy policy1

Related Commands


Command	Description
show ipv6 destination-guard policy	Displays destination guard information.

ipv6 dhcp-relay bulk-lease

To configure bulk lease query parameters, use the ipv6 dhcp-relay bulk-lease command in global configuration mode. To remove the bulk-lease query configuration, use the no form of this command.

ipv6 dhcp-relay bulk-lease {data-timeout seconds | retry number} [disable]

no ipv6 dhcp-relay bulk-lease [disable]

Syntax Description


data-timeout	(Optional) Bulk lease query data transfer timeout.
`seconds`	(Optional) The range is from 60 seconds to 600 seconds. The default is 300 seconds.
retry	(Optional) Sets the bulk lease query retries.
`number`	(Optional) The range is from 0 to 5. The default is 5.
disable	(Optional) Disables the DHCPv6 bulk lease query feature.

Command Default

Bulk lease query is enabled automatically when the DHCP for IPv6 (DHCPv6) relay agent feature is enabled.

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

Use the ipv6 dhcp-relay bulk-lease command in global configuration mode to configure bulk lease query parameters, such as data transfer timeout and bulk-lease TCP connection retries.

The DHCPv6 bulk lease query feature is enabled automatically when the DHCPv6 relay agent is enabled. The DHCPv6 bulk lease query feature itself cannot be enabled using this command. To disable this feature, use the ipv6 dhcp-relay bulk-lease command with the disable keyword.

Examples

The following example shows how to set the bulk lease query data transfer timeout to 60 seconds:


Device(config)# ipv6 dhcp-relay bulk-lease data-timeout 60

ipv6 dhcp-relay option vpn

To enable the DHCP for IPv6 relay VRF-aware feature, use the ipv6 dhcp-relay option vpn command in global configuration mode. To disable the feature, use the no form of this command.

ipv6 dhcp-relay option vpn

no ipv6 dhcp-relay option vpn

Syntax Description

This command has no arguments or keywords.

Command Default

The DHCP for IPv6 relay VRF-aware feature is not enabled on the router.

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

The ipv6 dhcp-relay option vpn command allows the DHCPv6 relay VRF-aware feature to be enabled globally on the router. If the ipv6 dhcp relay option vpn command is enabled on a specified interface, it overrides the global ipv6 dhcp-relay option vpn command.

Examples

The following example enables the DHCPv6 relay VRF-aware feature globally on the router:

Device(config)# ipv6 dhcp-relay option vpn

Related Commands


Command	Description
ipv6 dhcp relay option vpn	Enables the DHCPv6 relay VRF-aware feature on an interface.

ipv6 dhcp-relay source-interface

To configure an interface to use as the source when relaying messages, use the ipv6 dhcp-relay source-interface command in global configuration mode. To remove the interface from use as the source, use the no form of this command.

ipv6 dhcp-relay source-interface interface-type interface-number

no ipv6 dhcp-relay source-interface interface-type interface-number

Syntax Description


`interface-type` `interface-number`	(Optional) Interface type and number that specifies output interface for a destination. If this argument is configured, client messages are forwarded to the destination address through the link to which the output interface is connected.

Command Default

The address of the server-facing interface is used as the IPv6 relay source.

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

If the configured interface is shut down, or if all of its IPv6 addresses are removed, the relay will revert to its standard behavior.

The interface configuration (using the ipv6 dhcp relay source-interface command in interface configuration mode) takes precedence over the global configuration if both have been configured.

Examples

The following example configures the Loopback 0 interface to be used as the relay source:

Device(config)# ipv6 dhcp-relay source-interface loopback 0

Related Commands


Command	Description
ipv6 dhcp relay source-interface	Enables DHCP for IPv6 service on an interface.

ipv6 dhcp binding track ppp

To configure Dynamic Host Configuration Protocol (DHCP) for IPv6 to release any bindings associated with a PPP connection when that connection closes, use the ipv6 dhcp binding track ppp command in global configuration mode. To return to the default behavior, use the no form of this command.

ipv6 dhcp binding track ppp

no ipv6 dhcp binding track ppp

Syntax Description

This command has no arguments or keywords.

Command Default

When a PPP connection closes, the DHCP bindings associated with that connection are not released.

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

The ipv6 dhcp binding track ppp command configures DHCP for IPv6 to automatically release any bindings associated with a PPP connection when that connection is closed. The bindings are released automatically to accommodate subsequent new registrations by providing sufficient resource.

Note

In IPv6 broadband deployment using DHCPv6, you must enable release of prefix bindings associated with a PPP virtual interface using this command. This ensures that DHCPv6 bindings are tracked together with PPP sessions, and in the event of DHCP REBIND failure, the client initiates DHCPv6 negotiation again.

A binding table entry on the DHCP for IPv6 server is automatically:

Created whenever a prefix is delegated to a client from the configuration pool.
Updated when the client renews, rebinds, or confirms the prefix delegation.
Deleted when the client releases all the prefixes in the binding voluntarily, all prefixes’ valid lifetimes have expired, or an administrator clears the binding.

Examples

The following example shows how to release the prefix bindings associated with the PPP:


Device(config)# ipv6 dhcp binding track ppp

ipv6 dhcp database

To configure a Dynamic Host Configuration Protocol (DHCP) for IPv6 binding database agent, use the ipv6 dhcp database command in global configuration mode. To delete the database agent, use the no form of this command.

ipv6 dhcp database agent [write-delay seconds] [timeout seconds]

no ipv6 dhcp database agent

Syntax Description


`agent`	A flash, local bootflash, compact flash, NVRAM, FTP, TFTP, or Remote Copy Protocol (RCP) uniform resource locator.
write-delay `seconds`	(Optional) How often (in seconds) DHCP for IPv6 sends database updates. The default is 300 seconds. The minimum write delay is 60 seconds.
timeout `seconds`	(Optional) How long, in seconds, the router waits for a database transfer.

Command Default

Write-delay default is 300 seconds. Timeout default is 300 seconds.

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

The ipv6 dhcp database command specifies DHCP for IPv6 binding database agent parameters. The user may configure multiple database agents.

A binding table entry is automatically created whenever a prefix is delegated to a client from the configuration pool, updated when the client renews, rebinds, or confirms the prefix delegation, and deleted when the client releases all the prefixes in the binding voluntarily, all prefixes’ valid lifetimes have expired, or administrators enable the clear ipv6 dhcp binding command. These bindings are maintained in RAM and can be saved to permanent storage using the agent argument so that the information about configuration such as prefixes assigned to clients is not lost after a system reload or power down. The bindings are stored as text records for easy maintenance.

Each permanent storage to which the binding database is saved is called the database agent. A database agent can be a remote host such as an FTP server or a local file system such as NVRAM.

The write-delay keyword specifies how often, in seconds, that DHCP sends database updates. By default, DHCP for IPv6 server waits 300 seconds before sending any database changes.

The timeout keyword specifies how long, in seconds, the router waits for a database transfer. Infinity is defined as 0 seconds, and transfers that exceed the timeout period are aborted. By default, the DHCP for IPv6 server waits 300 seconds before aborting a database transfer. When the system is going to reload, there is no transfer timeout so that the binding table can be stored completely.

Examples

The following example specifies DHCP for IPv6 binding database agent parameters and stores binding entries in TFTP:


Device(config)# ipv6 dhcp database tftp://10.0.0.1/dhcp-binding

The following example specifies DHCP for IPv6 binding database agent parameters and stores binding entries in bootflash:

Device(config)# ipv6 dhcp database bootflash

Related Commands


Command	Description
clear ipv6 dhcp binding	Deletes automatic client bindings from the DHCP for IPv6 server binding table
show ipv6 dhcp database	Displays DHCP for IPv6 binding database agent information.

ipv6 dhcp iana-route-add

To add routes for individually assigned IPv6 addresses on a relay or server, use the ipv6 dhcp iana-route-add command in global configuration mode. To disable route addition for individually assigned IPv6 addresses on a relay or server, use the no form of the command.

ipv6 dhcp iana-route-add

no ipv6 dhcp iana-route-add

Syntax Description

This command has no arguments or keywords.

Command Default

Route addition for individually assigned IPv6 addresses on a relay or server is disabled by default.

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

The ipv6 dhcp iana-route-add command is disabled by default and has to be enabled if route addition is required. Route addition for Internet Assigned Numbers Authority (IANA) is possible if the client is connected to the relay or server through unnumbered interfaces, and if route addition is enabled with the help of this command.

Examples

The following example shows how to enable route addition for individually assigned IPv6 addresses:


Device(config)# ipv6 dhcp iana-route-add

ipv6 dhcp iapd-route-add

To enable route addition by Dynamic Host Configuration Protocol for IPv6 (DHCPv6) relay and server for the delegated prefix, use the ipv6 dhcp iapd-route-add command in global configuration mode. To disable route addition, use the no form of the command.

ipv6 dhcp iapd-route-add

no ipv6 dhcp iapd-route-add

Syntax Description

This command has no arguments or keywords.

Command Default

DHCPv6 relay and DHCPv6 server add routes for delegated prefixes by default.

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

The DHCPv6 relay and the DHCPv6 server add routes for delegated prefixes by default. The presence of this command on a router does not mean that routes will be added on that router. When you configure the command, routes for delegated prefixes will only be added on the first Layer 3 relay and server.

Examples

The following example shows how to enable the DHCPv6 relay and server to add routes for a delegated prefix:


Device(config)# ipv6 dhcp iapd-route-add

ipv6 dhcp-ldra

To enable Lightweight DHCPv6 Relay Agent (LDRA) functionality on an access node, use the ipv6 dhcp-ldra command in global configuration mode. To disable the LDRA functionality, use the no form of this command.

ipv6 dhcp-ldra {enable | disable}

no ipv6 dhcp-ldra {enable | disable}

Syntax Description


enable	Enables LDRA functionality on an access node.
disable	Disables LDRA functionality on an access node.

Command Default

By default, LDRA functionality is not enabled on an access node.

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

You must configure the LDRA functionality globally using the ipv6 dhcp-ldra command before configuring it on a VLAN or an access node (such as a Digital Subscriber Link Access Multiplexer [DSLAM] or an Ethernet switch) interface.

Examples

The following example shows how to enable the LDRA functionality:


Device(config)# ipv6 dhcp-ldra enable
Device(config)# exit

Note

In the above example, Device denotes an access node.

Related Commands


Command	Description
ipv6 dhcp ldra attach-policy	Enables LDRA functionality on a VLAN.
ipv6 dhcp-ldra attach-policy	Enables LDRA functionality on an interface.

ipv6 dhcp ping packets

To specify the number of packets a Dynamic Host Configuration Protocol for IPv6 (DHCPv6) server sends to a pool address as part of a ping operation, use the ipv6 dhcp ping packets command in global configuration mode. To prevent the server from pinging pool addresses, use the no form of this command.

ipv6 dhcp ping packets number

ipv6 dhcp ping packets

Syntax Description


`number`	The number of ping packets sent before the address is assigned to a requesting client. The valid range is from 0 to 10.

Command Default

No ping packets are sent before the address is assigned to a requesting client.

Command Modes

Global configuration (#)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

The DHCPv6 server pings a pool address before assigning the address to a requesting client. If the ping is unanswered, the server assumes, with a high probability, that the address is not in use and assigns the address to the requesting client.

Setting the number argument to 0 turns off the DHCPv6 server ping operation

Examples

The following example specifies four ping attempts by the DHCPv6 server before further ping attempts stop:


Device(config)# ipv6 dhcp ping packets 4

Related Commands


Command	Description
clear ipv6 dhcp conflict	Clears an address conflict from the DHCPv6 server database.
show ipv6 dhcp conflict	Displays address conflicts found by a DHCPv6 server, or reported through a DECLINE message from a client.

ipv6 dhcp pool

To configure a Dynamic Host Configuration Protocol (DHCP) for IPv6 server configuration information pool and enter DHCP for IPv6 pool configuration mode, use the ipv6 dhcp pool command in global configuration mode. To delete a DHCP for IPv6 pool, use the no form of this command.

ipv6 dhcp pool poolname

no ipv6 dhcp pool poolname

Syntax Description


`poolname`	User-defined name for the local prefix pool. The pool name can be a symbolic string (such as "Engineering") or an integer (such as 0).

Command Default

DHCP for IPv6 pools are not configured.

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

Use the ipv6 dhcp pool command to create a DHCP for IPv6 server configuration information pool. When the ipv6 dhcp pool command is enabled, the configuration mode changes to DHCP for IPv6 pool configuration mode. In this mode, the administrator can configure pool parameters, such as prefixes to be delegated and Domain Name System (DNS) servers, using the following commands:

address prefix IPv6-prefix [lifetime {valid-lifetime preferred-lifetime | infinite }] sets an address prefix for address assignment. This address must be in hexadecimal, using 16-bit values between colons.
link-address IPv6-prefix sets a link-address IPv6 prefix. When an address on the incoming interface or a link-address in the packet matches the specified IPv6-prefix, the server uses the configuration information pool. This address must be in hexadecimal, using 16-bit values between colons.
vendor-specific vendor-id enables DHCPv6 vendor-specific configuration mode. Specify a vendor identification number. This number is the vendor IANA Private Enterprise Number. The range is 1 to 4294967295. The following configuration command is available:
- suboption number sets vendor-specific suboption number. The range is 1 to 65535. You can enter an IPv6 address, ASCII text, or a hex string as defined by the suboption parameters.

Note

The hex value used under the suboption keyword allows users to enter only hex digits (0-f). Entering an invalid hex value does not delete the previous configuration.

Once the DHCP for IPv6 configuration information pool has been created, use the ipv6 dhcp server command to associate the pool with a server on an interface. If you do not configure an information pool, you need to use the ipv6 dhcp server interface configuration command to enable the DHCPv6 server function on an interface.

When you associate a DHCPv6 pool with an interface, only that pool services requests on the associated interface. The pool also services other interfaces. If you do not associate a DHCPv6 pool with an interface, it can service requests on any interface.

Not using any IPv6 address prefix means that the pool returns only configured options.

The link-address command allows matching a link-address without necessarily allocating an address. You can match the pool from multiple relays by using multiple link-address configuration commands inside a pool.

Since a longest match is performed on either the address pool information or the link information, you can configure one pool to allocate addresses and another pool on a subprefix that returns only configured options.

Examples

The following example specifies a DHCP for IPv6 configuration information pool named cisco1 and places the router in DHCP for IPv6 pool configuration mode:


Device(config)# ipv6 dhcp pool cisco1
Device(config-dhcpv6)#

The following example shows how to configure an IPv6 address prefix for the IPv6 configuration pool cisco1:

Device(config-dhcpv6)# address prefix 2001:1000::0/64
Device(config-dhcpv6)# end

The following example shows how to configure a pool named engineering with three link-address prefixes and an IPv6 address prefix:


Device# configure terminal
Device(config)# ipv6 dhcp pool engineering
Device(config-dhcpv6)# link-address 2001:1001::0/64Device(config-dhcpv6)# link-address 2001:1002::0/64Device(config-dhcpv6)# link-address 2001:2000::0/48Device(config-dhcpv6)# address prefix 2001:1003::0/64
Device(config-dhcpv6)# end

The following example shows how to configure a pool named 350 with vendor-specific options:


Device# configure terminal
Device(config)# ipv6 dhcp pool 350
Device(config-dhcpv6)# vendor-specific 9
Device(config-dhcpv6-vs)# suboption 1 address 1000:235D::1Device(config-dhcpv6-vs)# suboption 2 ascii "IP-Phone"
Device(config-dhcpv6-vs)# end

Related Commands


Command	Description
ipv6 dhcp server	Enables DHCP for IPv6 service on an interface.
show ipv6 dhcp pool	Displays DHCP for IPv6 configuration pool information.

ipv6 flow monitor

This command activates a previously created flow monitor by assigning it to the interface to analyze incoming or outgoing traffic.

To activate a previously created flow monitor, use the ipv6 flow monitor command. To de-activate a flow monitor, use the no form of the command.

ipv6 flow monitor ipv6-monitor-name [sampler ipv6-sampler-name] {input | output}

no ipv6 flow monitor ipv6-monitor-name [sampler ipv6-sampler-name] {input | output}

Syntax Description


`ipv6-monitor-name`	Activates a previously created flow monitor by assigning it to the interface to analyze incoming or outgoing traffic.
sampler `ipv6-sampler-name`	Applies the flow monitor sampler.
input	Applies the flow monitor on input traffic.
output	Applies the flow monitor on output traffic.

Command Default

IPv6 flow monitor is not activated until it is assigned to an interface.

Command Modes

Interface configuration (config-if)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

You cannot attach a NetFlow monitor to a port channel interface. If both service module interfaces are part of an EtherChannel, you should attach the monitor to both physical interfaces.

Examples

This example shows how to apply a flow monitor to an interface:

Device(config)# interface gigabitethernet 1/1/2
Device(config-if)# ip flow monitor FLOW-MONITOR-1 input
Device(config-if)# ip flow monitor FLOW-MONITOR-2 output
Device(config-if)# end

ipv6 dhcp server vrf enable

To enable the DHCP for IPv6 server VRF-aware feature, use the ipv6 dhcp server vrf enable command in global configuration mode. To disable the feature, use the no form of this command.

ipv6 dhcp server vrf enable

no ipv6 dhcp server vrf enable

Syntax Description

This command has no arguments or keywords.

Command Default

The DHCPv6 server VRF-aware feature is not enabled.

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

The ipv6 dhcp server option vpn command allows the DHCPv6 server VRF-aware feature to be enabled globally on a device.

Examples

The following example enables the DHCPv6 server VRF-aware feature globally on a device:

Device(config)# ipv6 dhcp server option vpn

ipv6 general-prefix

To define an IPv6 general prefix, use the ipv6 general-prefix command in global configuration mode. To remove the IPv6 general prefix, use the no form of this command.

ipv6 general-prefix prefix-name {ipv6-prefix/prefix-length | 6to4 interface-type interface-number | 6rd interface-type interface-number}

no ipv6 general-prefix prefix-name

Syntax Description


`prefix-name`	The name assigned to the prefix.
`ipv6-prefix`	The IPv6 network assigned to the general prefix. This argument must be in the form documented in RFC 2373 where the address is specified in hexadecimal using 16-bit values between colons. When defining a general prefix manually, specify both the `ipv6-prefix` and / `prefix-length` arguments.
/ `prefix-length`	The length of the IPv6 prefix. A decimal value that indicates how many of the high-order contiguous bits of the address comprise the prefix (the network portion of the address). A slash mark must precede the decimal value. When defining a general prefix manually, specify both the `ipv6-prefix` and / `prefix-length` arguments.
6to4	Allows configuration of a general prefix based on an interface used for 6to4 tunneling. When defining a general prefix based on a 6to4 interface, specify the 6to4 keyword and the `interface-type` `interface-number` argument.
`interface-type` `interface-number`	Interface type and number. For more information, use the question mark (? ) online help function. When defining a general prefix based on a 6to4 interface, specify the 6to4 keyword and the `interface-type` `interface-number` argument.
6rd	Allows configuration of a general prefix computed from an interface used for IPv6 rapid deployment (6RD) tunneling.

Command Default

No general prefix is defined.

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

Use the ipv6 general-prefix command to define an IPv6 general prefix.

A general prefix holds a short prefix, based on which a number of longer, more specific, prefixes can be defined. When the general prefix is changed, all of the more specific prefixes based on it will change, too. This function greatly simplifies network renumbering and allows for automated prefix definition.

More specific prefixes, based on a general prefix, can be used when configuring IPv6 on an interface.

When defining a general prefix based on an interface used for 6to4 tunneling, the general prefix will be of the form 2002:a.b.c.d::/48, where "a.b.c.d" is the IPv4 address of the interface referenced.

Examples

The following example manually defines an IPv6 general prefix named my-prefix:


Device(config)# ipv6 general-prefix my-prefix 2001:DB8:2222::/48

The following example defines an IPv6 general prefix named my-prefix based on a 6to4 interface:


Device(config)# ipv6 general-prefix my-prefix 6to4 ethernet0

Related Commands


Command	Description
show ipv6 general-prefix	Displays information on general prefixes for an IPv6 addresses.

ipv6 local policy route-map

To enable local policy-based routing (PBR) for IPv6 packets, use the ipv6 local policy route-map command in global configuration mode. To disable local policy-based routing for IPv6 packets, use the no form of this command.

ipv6 local policy route-map route-map-name

no ipv6 local policy route-map route-map-name

Syntax Description


`route-map-name`	Name of the route map to be used for local IPv6 PBR. The name must match a `route-map-name` value specified by the route-map command.

Command Default

IPv6 packets are not policy routed.

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

Packets originating from a router are not normally policy routed. However, you can use the ipv6 local policy route-map command to policy route such packets. You might enable local PBR if you want packets originated at the router to take a route other than the obvious shortest path.

The ipv6 local policy route-map command identifies a route map to be used for local PBR. The route-map commands each have a list of match and set commands associated with them. The match commands specify the match criteria, which are the conditions under which packets should be policy routed. The set commands specify set actions, which are particular policy routing actions to be performed if the criteria enforced by the match commands are met. The no ipv6 local policy route-map command deletes the reference to the route map and disables local policy routing.

Examples

In the following example, packets with a destination IPv6 address matching that allowed by access list pbr-src-90 are sent to the router at IPv6 address 2001:DB8::1:


ipv6 access-list src-90
 permit ipv6 host 2001::90 2001:1000::/64
route-map pbr-src-90 permit 10
 match ipv6 address src-90
 set ipv6 next-hop 2001:DB8::1
ipv6 local policy route-map pbr-src-90

Related Commands


Command	Description
ipv6 policy route-map	Configures IPv6 PBR on an interface.
match ipv6 address	Specifies an IPv6 access list to be used to match packets for PBR for IPv6.
match length	Bases policy routing on the Level 3 length of a packet.
route-map (IP)	Defines the conditions for redistributing routes from one routing protocol into another, or enables policy routing.
set default interface	Specifies the default interface to output packets that pass a match clause of a route map for policy routing and have no explicit route to the destination.
set interface	Specifies the default interface to output packets that pass a match clause of a route map for policy routing.
set ipv6 default next-hop	Specifies an IPv6 default next hop to which matching packets will be forwarded.
set ipv6 next-hop (PBR)	Indicates where to output IPv6 packets that pass a match clause of a route map for policy routing.
set ipv6 precedence	Sets the precedence value in the IPv6 packet header.

ipv6 local pool

To configure a local IPv6 prefix pool, use the ipv6 local pool configuration command with the prefix pool name. To disband the pool, use the no form of this command.

ipv6 local pool poolname prefix/prefix-length assigned-length [shared] [cache-size size]

no ipv6 local pool poolname

Syntax Description


`poolname`	User-defined name for the local prefix pool.
`prefix`	IPv6 prefix assigned to the pool. This argument must be in the form documented in RFC 2373 where the address is specified in hexadecimal using 16-bit values between colons.
/ `prefix-length`	The length of the IPv6 prefix assigned to the pool. A decimal value that indicates how many of the high-order contiguous bits of the address comprise the prefix (the network portion of the address).
`assigned-length`	Length of prefix, in bits, assigned to the user from the pool. The value of the `assigned-length` argument cannot be less than the value of the / `prefix-length` argument.
shared	(Optional) Indicates that the pool is a shared pool.
cache-size `size`	(Optional) Specifies the size of the cache.

Command Default

No pool is configured.

Command Modes

Global configuration (global)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

All pool names must be unique.

IPv6 prefix pools have a function similar to IPv4 address pools. Contrary to IPv4, a block of addresses (an address prefix) are assigned and not single addresses.

Prefix pools are not allowed to overlap.

Once a pool is configured, it cannot be changed. To change the configuration, the pool must be removed and recreated. All prefixes already allocated will also be freed.

Examples

This example shows the creation of an IPv6 prefix pool:


Device(config)# ipv6 local pool pool1 2001:0DB8::/29 64
Device(config)# end
Device# show ipv6 local pool
Pool Prefix Free In use 
pool1  2001:0DB8::/29  65516  20

Related Commands


Command	Description
debug ipv6 pool	Enables IPv6 pool debugging.
peer default ipv6 address pool	Specifies the pool from which client prefixes are assigned for PPP links.
prefix-delegation pool	Specifies a named IPv6 local prefix pool from which prefixes are delegated to DHCP for IPv6 clients.
show ipv6 local pool	Displays information about any defined IPv6 address pools.

ipv6 mld snooping

To enable Multicast Listener Discovery version 2 (MLDv2) protocol snooping globally, use the ipv6 mld snooping command in global configuration mode. To disable the MLDv2 snooping globally, use the no form of this command.

ipv6 mld snooping

no ipv6 mld snooping

Syntax Description

This command has no arguments or keywords.

Command Default

This command is enabled.

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced on the Supervisor Engine 720.

Usage Guidelines

MLDv2 snooping is supported on the Supervisor Engine 720 with all versions of the Policy Feature Card 3 (PFC3).

To use MLDv2 snooping, configure a Layer 3 interface in the subnet for IPv6 multicast routing or enable the MLDv2 snooping querier in the subnet.

Examples

This example shows how to enable MLDv2 snooping globally:


Device(config)# ipv6 mld snooping

Related Commands


Command	Description
show ipv6 mld snooping	Displays MLDv2 snooping information.

ipv6 mld ssm-map enable

To enable the Source Specific Multicast (SSM) mapping feature for groups in the configured SSM range, use the ipv6 mld ssm-map enable command in global configuration mode. To disable this feature, use the no form of this command.

ipv6 mld [vrf vrf-name] ssm-map enable

no ipv6 mld [vrf vrf-name] ssm-map enable

Syntax Description


vrf `vrf-name`	(Optional) Specifies a virtual routing and forwarding (VRF) configuration.

Command Default

The SSM mapping feature is not enabled.

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

The ipv6 mld ssm-map enable command enables the SSM mapping feature for groups in the configured SSM range. When the ipv6 mld ssm-map enable command is used, SSM mapping defaults to use the Domain Name System (DNS).

SSM mapping is applied only to received Multicast Listener Discovery (MLD) version 1 or MLD version 2 membership reports.

Examples

The following example shows how to enable the SSM mapping feature:

Device(config)# ipv6 mld ssm-map enable

Related Commands


Command	Description
debug ipv6 mld ssm-map	Displays debug messages for SSM mapping.
ipv6 mld ssm-map query dns	Enables DNS-based SSM mapping.
ipv6 mld ssm-map static	Configures static SSM mappings.
show ipv6 mld ssm-map	Displays SSM mapping information.

ipv6 mld state-limit

To limit the number of Multicast Listener Discovery (MLD) states globally, use the ipv6 mld state-limit command in global configuration mode. To disable a configured MLD state limit, use the no form of this command.

ipv6 mld [vrf vrf-name] state-limit number

no ipv6 mld [vrf vrf-name] state-limit number

Syntax Description


vrf `vrf-name`	(Optional) Specifies a virtual routing and forwarding (VRF) configuration.
`number`	Maximum number of MLD states allowed on a router. The valid range is from 1 to 64000.

Command Default

No default number of MLD limits is configured. You must configure the number of maximum MLD states allowed globally on a router when you configure this command.

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

Use the ipv6 mld state-limit command to configure a limit on the number of MLD states resulting from MLD membership reports on a global basis. Membership reports sent after the configured limits have been exceeded are not entered in the MLD cache and traffic for the excess membership reports is not forwarded.

Use the ipv6 mld limit command in interface configuration mode to configure the per-interface MLD state limit.

Per-interface and per-system limits operate independently of each other and can enforce different configured limits. A membership state will be ignored if it exceeds either the per-interface limit or global limit.

Examples

The following example shows how to limit the number of MLD states on a router to 300:


Device(config)# ipv6 mld state-limit 300

Related Commands


Command	Description
ipv6 mld access-group	Enables the performance of IPv6 multicast receiver access control.
ipv6 mld limit	Limits the number of MLD states resulting from MLD membership state on a per-interface basis.

ipv6 multicast-routing

To enable multicast routing using Protocol Independent Multicast (PIM) and Multicast Listener Discovery (MLD) on all IPv6-enabled interfaces of the router and to enable multicast forwarding, use the ipv6 multicast-routing command in global configuration mode. To stop multicast routing and forwarding, use the no form of this command.

ipv6 multicast-routing [vrf vrf-name]

no ipv6 multicast-routing

Syntax Description


vrf `vrf-name`	(Optional) Specifies a virtual routing and forwarding (VRF) configuration.

Command Default

Multicast routing is not enabled.

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

Use the ipv6 multicast-routing command to enable multicast forwarding. This command also enables Protocol Independent Multicast (PIM) and Multicast Listener Discovery (MLD) on all IPv6-enabled interfaces of the router being configured.

You can configure individual interfaces before you enable multicast so that you can then explicitly disable PIM and MLD protocol processing on those interfaces, as needed. Use the no ipv6 pim or the no ipv6 mld router command to disable IPv6 PIM or MLD router-side processing, respectively.

Examples

The following example enables multicast routing and turns on PIM and MLD on all interfaces:


Device(config)# ipv6 multicast-routing

Related Commands


Command	Description
ipv6 pim rp-address	Configures the address of a PIM RP for a particular group range.
no ipv6 pim	Turns off IPv6 PIM on a specified interface.
no ipv6 mld router	Disables MLD router-side processing on a specified interface.

ipv6 multicast group-range

To disable multicast protocol actions and traffic forwarding for unauthorized groups or channels on all the interfaces in a router, use the ipv6 multicast group-range command in global configuration mode. To return to the command’s default settings, use the no form of this command.

ipv6 multicast [vrf vrf-name] group-range [access-list-name]

no ipv6 multicast [vrf vrf-name] group-range [access-list-name]

Syntax Description


vrf `vrf-name`	(Optional) Specifies a virtual routing and forwarding (VRF) configuration.
`access-list-name`	(Optional) Name of an access list that contains authenticated subscriber groups and authorized channels that can send traffic to the router.

Command Default

Multicast is enabled for groups and channels permitted by a specified access list and disabled for groups and channels denied by a specified access list.

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

The ipv6 multicast group-range command provides an access control mechanism for IPv6 multicast edge routing. The access list specified by the access-list-name argument specifies the multicast groups or channels that are to be permitted or denied. For denied groups or channels, the router ignores protocol traffic and actions (for example, no Multicast Listener Discovery (MLD) states are created, no mroute states are created, no Protocol Independent Multicast ( PIM) joins are forwarded), and drops data traffic on all interfaces in the system, thus disabling multicast for denied groups or channels.

Using the ipv6 multicast group-range global configuration command is equivalent to configuring the MLD access control and multicast boundary commands on all interfaces in the system. However, the ipv6 multicast group-range command can be overridden on selected interfaces by using the following interface configuration commands:

ipv6 mld access-group access-list-name
ipv6 multicast boundary scope scope-value

Because the no ipv6 multicast group-range command returns the router to its default configuration, existing multicast deployments are not broken.

Examples

The following example ensures that the router disables multicast for groups or channels denied by an access list named list2:


Device(config)# ipv6 multicast group-range list2

The following example shows that the command in the previous example is overridden on an interface specified by int2:


Device(config)# interface int2
Device(config-if)# ipv6 mld access-group int-list2

On int2, MLD states are created for groups or channels permitted by int-list2 but are not created for groups or channels denied by int-list2. On all other interfaces, the access-list named list2 is used for access control.

In this example, list2 can be specified to deny all or most multicast groups or channels, and int-list2 can be specified to permit authorized groups or channels only for interface int2.

Related Commands


Command	Description
ipv6 mld access-group	Performs IPv6 multicast receiver access control.
ipv6 multicast boundary scope	Configures a multicast boundary on the interface for a specified scope.

ipv6 multicast pim-passive-enable

To enable the Protocol Independent Multicast (PIM) passive feature on an IPv6 router, use the ipv6 multicast pim-passive-enable command in global configuration mode. To disable this feature, use the no form of this command.

ipv6 multicast pim-passive-enable

no ipv6 multicast pim-passive-enable

Syntax Description

This command has no arguments or keywords.

Command Default

PIM passive mode is not enabled on the router.

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

Use the ipv6 multicast pim-passive-enable command to configure IPv6 PIM passive mode on a router. Once PIM passive mode is configured globally, use the ipv6 pim passive command in interface configuration mode to configure PIM passive mode on a specific interface.

Examples

The following example configures IPv6 PIM passive mode on a router:


Device(config)# ipv6 multicast pim-passive-enable

Related Commands


Command	Description
ipv6 pim passive	Configures PIM passive mode on a specific interface.

ipv6 multicast rpf

To enable IPv6 multicast reverse path forwarding (RPF) check to use Border Gateway Protocol (BGP) unicast routes in the Routing Information Base (RIB), use the ipv6 multicast rpf command in global configuration mode. To disable this function, use the no form of this command.

ipv6 multicast [vrf vrf-name] rpf {backoff initial-delay max-delay | use-bgp}

no ipv6 multicast [vrf vrf-name] rpf {backoff initial-delay max-delay | use-bgp}

Syntax Description


vrf `vrf-name`	(Optional) Specifies a virtual routing and forwarding (VRF) configuration.
backoff	Specifies the backoff delay after a unicast routing change.
`initial-delay`	Initial RPF backoff delay, in milliseconds (ms). The range is from 200 to 65535.
`max-delay`	Maximum RPF backoff delay, in ms. The range is from 200 to 65535.
use-bgp	Specifies to use BGP routes for multicast RPF lookups.

Command Default

The multicast RPF check does not use BGP unicast routes.

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

When the ipv6 multicast rpf command is configured, multicast RPF check uses BGP unicast routes in the RIB. This is not done by default.

Examples

The following example shows how to enable the multicast RPF check function:


Device(config)# ipv6 multicast rpf use-bgp

Related Commands


Command	Description
ipv6 multicast limit	Configure per-interface multicast route (mroute) state limiters in IPv6.
ipv6 multicast multipath	Enables load splitting of IPv6 multicast traffic across multiple equal-cost paths.

ipv6 nd cache expire

To configure the length of time before an IPv6 neighbor discovery (ND) cache entry expires, use the ipv6 nd cache expire command in interface configuration mode. To remove this configuration, use the no form of this command.

ipv6 nd cache expire expire-time-in-seconds [refresh]

no ipv6 nd cache expire expire-time-in-seconds [refresh]

Syntax Description


`expire-time-in-seconds`	The time range is from 1 through 65536 seconds. The default is 14400 seconds, or 4 hours.
refresh	(Optional) Automatically refreshes the ND cache entry.

Command Default

This expiration time is 14400 seconds (4 hours)

Command Modes

Interface configuration (config-if)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

By default, an ND cache entry is expired and deleted if it remains in the STALE state for 14,400 seconds, or 4 hours. The ipv6 nd cache expire command allows the user to vary the expiry time and to trigger autorefresh of an expired entry before the entry is deleted.

When the refresh keyword is used, an ND cache entry is autorefreshed. The entry moves into the DELAY state and the neighbor unreachability detection (NUD) process occurs, in which the entry transitions from the DELAY state to the PROBE state after 5 seconds. When the entry reaches the PROBE state, a neighbor solicitation (NS) is sent and then retransmitted as per the configuration.

Examples

The following example shows that the ND cache entry is configured to expire in 7200 seconds, or 2 hours:


Device(config-if)# ipv6 nd cache expire 7200

ipv6 nd cache interface-limit (global)

To configure a neighbor discovery cache limit on all interfaces on the device, use the ipv6 nd cache interface-limit command in global configuration mode. To remove the neighbor discovery from all interfaces on the device, use the no form of this command.

ipv6 nd cache interface-limit size [log rate]

no ipv6 nd cache interface-limit size [log rate]

Syntax Description


`size`	Cache size.
log `rate`	(Optional) Adjustable logging rate, in seconds. The valid values are 0 and 1.

Command Default

Default logging rate for the device is one entry every second.

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

The ipv6 nd cache interface-limit command in global configuration mode imposes a common per-interface cache size limit on all interfaces on the device.

Issuing the no or default form of the command will remove the neighbor discovery limit from every interface on the device that was configured using global configuration mode. It will not remove the neighbor discovery limit from any interface configured using the ipv6 nd cache interface-limit command in interface configuration mode.

The default (and maximum) logging rate for the device is one entry every second.

Examples

The following example shows how to set a common per-interface cache size limit of 4 seconds on all interfaces on the device:

Device(config)# ipv6 nd cache interface-limit 4

Related Commands


Command	Description
ipv6 nd cache interface-limit (interface)	Configures a neighbor discovery cache limit on a specified interface on the device.

ipv6 nd host mode strict

To enable the conformant, or strict, IPv6 host mode, use the ipv6 nd host mode strict command in global configuration mode. To reenable conformant, or loose, IPv6 host mode, use the no form of this command.

ipv6 nd host mode strict

Syntax Description

This command has no arguments or keywords.

Command Default

Nonconformant, or loose, IPv6 host mode is enabled.

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

The default IPv6 host mode type is loose, or nonconformant. To enable IPv6 strict, or conformant, host mode, use the ipv6 nd host mode strict command. You can change between the two IPv6 host modes using the no form of this command.

The ipv6 nd host mode strict command selects the type of IPv6 host mode behavior and enters interface configuration mode. However, the ipv6 nd host mode strict command is ignored if you have configured IPv6 routing with the ipv6 unicast-routing command. In this situation, the default IPv6 host mode type, loose, is used.

Examples

The following example shows how to configure the device as a strict IPv6 host and enables IPv6 address autoconfiguration on Ethernet interface 0/0:

Device(config)# ipv6 nd host mode strict
Device(config-if)# interface ethernet0/0
Device(config-if)# ipv6 address autoconfig

The following example shows how to configure the device as a strict IPv6 host and configures a static IPv6 address on Ethernet interface 0/0:

Device(config)# ipv6 nd host mode strict
Device(config-if)# interface ethernet0/0
Device(config-if)# ipv6 address 2001::1/64

Related Commands


Command	Description
ipv6 unicast-routing	Enables the forwarding of IPv6 unicast datagrams.

ipv6 nd ns-interval

To configure the interval between IPv6 neighbor solicitation (NS) retransmissions on an interface, use the ipv6 nd ns-interval command in interface configuration mode. To restore the default interval, use the no form of this command.

ipv6 nd ns-interval milliseconds

no ipv6 nd ns-interval

Syntax Description


`milliseconds`	The interval between IPv6 neighbor solicit transmissions for address resolution. The acceptable range is from 1000 to 3600000 milliseconds.

Command Default

0 milliseconds (unspecified) is advertised in router advertisements and the value 1000 is used for the neighbor discovery activity of the router itself.

Command Modes

Interface configuration (config-if)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

By default, using the ipv6 nd ns-interval command changes the NS retransmission interval for both address resolution and duplicate address detection (DAD). To specify a different NS retransmission interval for DAD, use the ipv6 nd dad time command.

This value will be included in all IPv6 router advertisements sent out this interface. Very short intervals are not recommended in normal IPv6 operation. When a nondefault value is configured, the configured time is both advertised and used by the router itself.

Examples

The following example configures an IPv6 neighbor solicit transmission interval of 9000 milliseconds for Ethernet interface 0/0:


Device(config)# interface ethernet 0/0
Device(config-if)# ipv6 nd ns-interval 9000

Related Commands


Command	Description
ipv6 nd dad time	Configures the NS retransmit interval for DAD separately from the NS retransmit interval for address resolution.
show ipv6 interface	Displays the usability status of interfaces configured for IPv6.

ipv6 nd reachable-time

To configure the amount of time that a remote IPv6 node is considered reachable after some reachability confirmation event has occurred, use the ipv6 nd reachable-time command in interface configuration mode. To restore the default time, use the no form of this command.

ipv6 nd reachable-time milliseconds

no ipv6 nd reachable-time

Syntax Description


`milliseconds`	The amount of time that a remote IPv6 node is considered reachable (in milliseconds).

Command Default

0 milliseconds (unspecified) is advertised in router advertisements and the value 30000 (30 seconds) is used for the neighbor discovery activity of the router itself.

Command Modes

Interface configuration (config-if)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

The configured time enables the router to detect unavailable neighbors. Shorter configured times enable the router to detect unavailable neighbors more quickly; however, shorter times consume more IPv6 network bandwidth and processing resources in all IPv6 network devices. Very short configured times are not recommended in normal IPv6 operation.

The configured time is included in all router advertisements sent out of an interface so that nodes on the same link use the same time value. A value of 0 means indicates that the configured time is unspecified by this router.

Examples

The following example configures an IPv6 reachable time of 1,700,000 milliseconds for Ethernet interface 0/0:

Device(config)# interface ethernet 0/0
Device(config-if)# ipv6 nd reachable-time 1700000

Related Commands


Command	Description
show ipv6 interface	Displays the usability status of interfaces configured for IPv6.

ipv6 nd resolution data limit

To configure the number of data packets queued pending Neighbor Discovery resolution, use the ipv6 nd resolution data limit command in global configuration mode.

ipv6 nd resolution data limit number-of-packets

no ipv6 nd resolution data limit number-of-packets

Syntax Description


`number-of-packets`	The number of queued data packets. The range is from 16 to 2048 packets.

Command Default

Queue limit is 16 packets.

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

The ipv6 nd resolution data limit command allows the customer to configure the number of data packets queued pending Neighbor Discovery resolution. IPv6 Neighbor Discovery queues a data packet that initiates resolution for an unresolved destination. Neighbor Discovery will only queue one packet per destination. Neighbor Discovery also enforces a global (per-router) limit on the number of packets queued. Once the global queue limit is reached, further packets to unresolved destinations are discarded. The minimum (and default) value is 16 packets, and the maximum value is 2048.

In most situations, the default value of 16 queued packets pending Neighbor Discovery resolution is sufficient. However, in some high-scalability scenarios in which the router needs to initiate communication with a very large number of neighbors almost simultaneously, then the value may be insufficient. This may lead to loss of the initial packet sent to some neighbors. In most applications, the initial packet is retransmitted, so initial packet loss generally is not a cause for concern. (Note that dropping the initial packet to an unresolved destination is normal in IPv4.) However, there may be some high-scale configurations where loss of the initial packet is inconvenient. In these cases, the customer can use the ipv6 nd resolution data limit command to prevent the initial packet loss by increasing the unresolved packet queue size.

Examples

The following example configures the global number of data packets held awaiting resolution to be 32:


Device(config)# ipv6 nd resolution data limit 32

ipv6 nd route-owner

To insert Neighbor Discovery-learned routes into the routing table with "ND" status and to enable ND autoconfiguration behavior, use the ipv6 nd route-owner command. To remove this information from the routing table, use the no form of this command.

ipv6 nd route-owner

Syntax Description

This command has no arguments or keywords.

Command Default

The status of Neighbor Discovery-learned routes is "Static."

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

The ipv6 nd route-owner command inserts routes learned by Neighbor Discovery into the routing table with a status of "ND" rather than "Static" or "Connected."

This global command also enables you to use the ipv6 nd autoconfig default or ipv6 nd autoconfig prefix commands in interface configuration mode. If the ipv6 nd route-owner command is not issued, then the ipv6 nd autoconfig default and ipv6 nd autoconfig prefix commands are accepted by the router but will not work.

Examples

Device(config)# ipv6 nd route-owner

Related Commands


Command	Description
ipv6 nd autoconfig default	Allows Neighbor Discovery to install a default route to the Neighbor Discovery-derived default router.
ipv6 nd autoconfig prefix	Uses Neighbor Discovery to install all valid on-link prefixes from RAs received on the interface.

ipv6 neighbor

To configure a static entry in the IPv6 neighbor discovery cache, use the ipv6 neighbor command in global configuration mode. To remove a static IPv6 entry from the IPv6 neighbor discovery cache, use the no form of this command.

ipv6 neighbor ipv6-address interface-type interface-number hardware-address

no ipv6 neighbor ipv6-address interface-type interface-number

Syntax Description


`ipv6-address`	The IPv6 address that corresponds to the local data-link address. This argument must be in the form documented in RFC 2373 where the address is specified in hexadecimal using 16-bit values between colons.
`interface-type`	The specified interface type. For supported interface types, use the question mark (?) online help function.
`interface-number`	The specified interface number.
`hardware-address`	The local data-link address (a 48-bit address).

Command Default

Static entries are not configured in the IPv6 neighbor discovery cache.

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

The ipv6 neighbor command is similar to the arp (global) command.

If an entry for the specified IPv6 address already exists in the neighbor discovery cache--learned through the IPv6 neighbor discovery process--the entry is automatically converted to a static entry.

Use the show ipv6 neighbors command to view static entries in the IPv6 neighbor discovery cache. A static entry in the IPv6 neighbor discovery cache can have one of the following states:

INCMP (Incomplete)--The interface for this entry is down.
REACH (Reachable)--The interface for this entry is up.

Note

Reachability detection is not applied to static entries in the IPv6 neighbor discovery cache; therefore, the descriptions for the INCMP and REACH states are different for dynamic and static cache entries. See the show ipv6 neighbors command for descriptions of the INCMP and REACH states for dynamic cache entries.

The clear ipv6 neighbors command deletes all entries in the IPv6 neighbor discovery cache, except static entries. The no ipv6 neighbor command deletes a specified static entry from the neighbor discovery cache; the command does not remove dynamic entries--learned from the IPv6 neighbor discovery process--from the cache. Disabling IPv6 on an interface by using the no ipv6 enable command or the no ipv6 unnumbered command deletes all IPv6 neighbor discovery cache entries configured for that interface, except static entries (the state of the entry changes to INCMP).

Static entries in the IPv6 neighbor discovery cache are not modified by the neighbor discovery process.

Note

Static entries for IPv6 neighbors can be configured only on IPv6-enabled LAN and ATM LAN Emulation interfaces.

Examples

The following example configures a static entry in the IPv6 neighbor discovery cache for a neighbor with the IPv6 address 2001:0DB8::45A and link-layer address 0002.7D1A.9472 on Ethernet interface 1:


Device(config)# ipv6 neighbor 2001:0DB8::45A ethernet1 0002.7D1A.9472

Related Commands


Command	Description
arp (global)	Adds a permanent entry in the ARP cache.
clear ipv6 neighbors	Deletes all entries in the IPv6 neighbor discovery cache, except static entries.
no ipv6 enable	Disables IPv6 processing on an interface that has not been configured with an explicit IPv6 address.
no ipv6 unnumbered	Disables IPv6 on an unnumbered interface.
show ipv6 neighbors	Displays IPv6 neighbor discovery cache information.

ipv6 ospf name-lookup

To display Open Shortest Path First (OSPF) router IDs as Domain Naming System (DNS) names, use the ipv6 ospf name-lookup command in global configuration mode. To stop displaying OSPF router IDs as DNS names, use the no form of this command.

ipv6 ospf name-lookup

no ipv6 ospf name-lookup

Syntax Description

This command has no arguments or keywords.

Command Default

This command is disabled by default

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

This command makes it easier to identify a router because the router is displayed by name rather than by its router ID or neighbor ID.

Examples

The following example configures OSPF to look up DNS names for use in all OSPF show EXEC command displays:


Device(config)# ipv6 ospf name-lookup

ipv6 pim

To reenable IPv6 Protocol Independent Multicast (PIM) on a specified interface, use the ipv6 pim command in interface configuration mode. To disable PIM on a specified interface, use the no form of the command.

ipv6 pim

no ipv6 pim

Syntax Description

This command has no arguments or keywords.

Command Default

PIM is automatically enabled on every interface.

Command Modes

Interface configuration (config-if)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

After a user has enabled the ipv6 multicast-routing command, PIM is enabled to run on every interface. Because PIM is enabled on every interface by default, use the no form of the ipv6 pim command to disable PIM on a specified interface. When PIM is disabled on an interface, it does not react to any host membership notifications from the Multicast Listener Discovery (MLD) protocol.

Examples

The following example turns off PIM on Fast Ethernet interface 1/0:


Device(config)# interface FastEthernet 1/0
Device(config-if)# no ipv6 pim

Related Commands


Command	Description
ipv6 multicast-routing	Enables multicast routing using PIM and MLD on all IPv6-enabled interfaces of the router and enables multicast forwarding.

ipv6 pim accept-register

To accept or reject registers at the rendezvous point (RP), use the ipv6 pim accept-register command in global configuration mode. To return to the default value, use the no form of this command.

ipv6 pim [vrf vrf-name] accept-register {list access-list | route-map map-name}

no ipv6 pim [vrf vrf-name] accept-register {list access-list | route-map map-name}

Syntax Description


vrf `vrf-name`	(Optional) Specifies a virtual routing and forwarding (VRF) configuration.
list `access-list`	Defines the access list name.
route-map `map-name`	Defines the route map.

Command Default

All sources are accepted at the RP.

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

Use the ipv6 pim accept-register command to configure a named access list or route map with match attributes. When the permit conditions as defined by the access-list and map-name arguments are met, the register message is accepted. Otherwise, the register message is not accepted, and an immediate register-stop message is returned to the encapsulating designated router.

Examples

The following example shows how to filter on all sources that do not have a local multicast Border Gateway Protocol (BGP) prefix:


ipv6 pim accept-register route-map reg-filter
route-map reg-filter permit 20
 match as-path 101
ip as-path access-list 101 permit

ipv6 pim allow-rp

To enable the PIM Allow RP feature for all IP multicast-enabled interfaces in an IPv6 device, use the ip pim allow-rp command in global configuration mode. To return to the default value, use the no form of this command.

ipv6 pim allow-rp [group-list access-list | rp-list access-list [group-list access-list]]

no ipv6 pim allow-rp

Syntax Description


group-list	(Optional) Identifies an access control list (ACL) of allowed group ranges for PIM Allow RP.
rp-list	(Optional) Specifies an ACL for allowed rendezvous-point (RP) addresses for PIM Allow RP.
`access-list`	(Optional) Unique number or name of a standard ACL.

Command Default

PIM Allow RP is disabled.

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

Use this command to enable the receiving device in an IP multicast network to accept a (*, G) Join from an unexpected (different) RP address.

Before enabling PIM Allow RP, you must first use the ipv6 pim rp-address command to define an RP.

Related Commands


Command	Description
ipv6 pim rp-address	Statically configures the address of a PIM RP for multicast groups.

ipv6 pim anycast-RP

To configure the address of the Protocol-Independent Multicast (PIM) rendezvous point (RP) for an anycast group range, use the ipv6 pim anycast-RP command in global configuration mode. To remove an RP address for an anycast group range, use the no form of this command.

ipv6 pim anycast-RP { rp-address peer-address}

no ipv6 pim anycast-RP

Syntax Description


`anycast-rp-address`	Anycast RP set for the RP assigned to the group range. This is the address that first-hop and last-hop PIM routers use to register and join.
`peer-address`	The address to which register messages copies are sent. This address is any address assigned to the RP router, not including the address assigned using the `anycast-rp-address` variable.

Command Default

No PIM RP address is configured for an anycast group range.

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

The anycast RP feature is useful when interdomain connection is not required. Use this command to configure the address of the PIM RP for an anycast group range.

Examples


Device# ipv6 pim anycast-rp 2001:DB8::1:1 2001:DB8::3:3

Related Commands


Command	Description
show ipv6 pim anycast-RP	Verifies IPv6 PIM RP anycast configuration.

ipv6 pim neighbor-filter list

To filter Protocol Independent Multicast (PIM) neighbor messages from specific IPv6 addresses, use the ipv6 pim neighbor-filter command in the global configuration mode. To return to the router default, use the no form of this command.

ipv6 pim [vrf vrf-name] neighbor-filter list access-list

no ipv6 pim [vrf vrf-name] neighbor-filter list access-list

Syntax Description


vrf `vrf-name`	(Optional) Specifies a virtual routing and forwarding (VRF) configuration.
`access-list`	Name of an IPv6 access list that denies PIM hello packets from a source.

Command Default

PIM neighbor messages are not filtered.

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

The ipv6 pim neighbor-filter list command is used to prevent unauthorized routers on the LAN from becoming PIM neighbors. Hello messages from addresses specified in this command are ignored.

Examples

The following example causes PIM to ignore all hello messages from IPv6 address FE80::A8BB:CCFF:FE03:7200:


Device(config)# ipv6 pim neighbor-filter list nbr_filter_acl
Device(config)# ipv6 access-list nbr_filter_acl
Device(config-ipv6-acl)# deny ipv6 host FE80::A8BB:CCFF:FE03:7200 any
Device(config-ipv6-acl)# permit any any

ipv6 pim rp-address

To configure the address of a Protocol Independent Multicast (PIM) rendezvous point (RP) for a particular group range, use the ipv6 pim rp-address command in global configuration mode. To remove an RP address, use the no form of this command.

ipv6 pim [vrf vrf-name] rp-address ipv6-address [group-access-list] [bidir]

no ipv6 pim rp-address ipv6-address [group-access-list] [bidir]

Syntax Description


vrf `vrf-name`	(Optional) Specifies a virtual routing and forwarding (VRF) configuration.
`ipv6-address`	The IPv6 address of a router to be a PIM RP. The `ipv6-address` argument must be in the form documented in RFC 2373 where the address is specified in hexadecimal using 16-bit values between colons.
`group-access-list`	(Optional) Name of an access list that defines for which multicast groups the RP should be used. If the access list contains any group address ranges that overlap the assigned source-specific multicast (SSM) group address range (FF3x::/96), a warning message is displayed, and the overlapping ranges are ignored. If no access list is specified, the specified RP is used for all valid multicast non-SSM address ranges. To support embedded RP, the router configured as the RP must use a configured access list that permits the embedded RP group ranges derived from the embedded RP address. Note that the embedded RP group ranges need not include all the scopes (for example, 3 through 7).
bidir	(Optional) Indicates that the group range will be used for bidirectional shared-tree forwarding; otherwise, it will be used for sparse-mode forwarding. A single IPv6 address can be configured to be RP only for either bidirectional or sparse-mode group ranges. A single group-range list can be configured to operate either in bidirectional or sparse mode.

Command Default

No PIM RPs are preconfigured. Embedded RP support is enabled by default when IPv6 PIM is enabled (where embedded RP support is provided). Multicast groups operate in PIM sparse mode.

Command Modes

Global configuration (config)

Command History


Release	Modification
Cisco IOS XE Everest 16.6.1	This command was introduced.

Usage Guidelines

When PIM is configured in sparse mode, you must choose one or more routers to operate as the RP. An RP is a single common root of a shared distribution tree and is statically configured on each router.

Where embedded RP support is available, only the RP needs to be statically configured as the RP for the embedded RP ranges. No additional configuration is needed on other IPv6 PIM routers. The other routers will discover the RP address from the IPv6 group address. If these routers want to select a static RP instead of the embedded RP, the specific embedded RP group range must be configured in the access list of the static RP.

The RP address is used by first-hop routers to send register packets on behalf of source multicast hosts. The RP address is also used by routers on behalf of multicast hosts that want to become members of a group. These routers send join and prune messages to the RP.

If the optional group-access-list argument is not specified, the RP is applied to the entire routable IPv6 multicast group range, excluding SSM, which ranges from FFX[3-f]::/8 to FF3X::/96. If the group-access-list argument is specified, the IPv6 address is the RP address for the group range specified in the group-access-list argument.

You can configure Cisco IOS software to use a single RP for more than one group. The conditions specified by the access list determine which groups the RP can be used for. If no access list is configured, the RP is used for all groups.

A PIM router can use multiple RPs, but only one per group.

Examples

The following example shows how to set the PIM RP address to 2001::10:10 for all multicast groups:


Device(config)# ipv6 pim rp-address 2001::10:10

The following example sets the PIM RP address to 2001::10:10 for the multicast group FF04::/64 only:


Device(config)# ipv6 access-list acc-grp-1
Device(config-ipv6-acl)# permit ipv6 any ff04::/64
Device(config)# ipv6 pim rp-address 2001::10:10 acc-grp-1

The following example shows how to configure a group access list that permits the embedded RP ranges derived from the IPv6 RP address 2001:0DB8:2::2:


Device(config)# ipv6 pim rp-address 2001:0DB8:2::2 embd-ranges
Device(config)# ipv6 access-list embd-ranges
Device(config-ipv6-acl)# permit ipv6 any ff73:240:2:2:2::/96
Device(config-ipv6-acl)# permit ipv6 any ff74:240:2:2:2::/96
Device(config-ipv6-acl)# permit ipv6 any ff75:240:2:2:2::/96
Device(config-ipv6-acl)# permit ipv6 any ff76:240:2:2:2::/96
Device(config-ipv6-acl)# permit ipv6 any ff77:240:2:2:2::/96
Device(config-ipv6-acl)# permit ipv6 any ff78:240:2:2:2::/96

The following example shows how to enable the address 100::1 as the bidirectional RP for the entries multicast range FF::/8:


ipv6 pim rp-address 100::1 bidir

In the following example, the IPv6 address 200::1 is enabled as the bidirectional RP for the ranges permitted by the access list named bidir-grps. The ranges permitted by this list are ff05::/16 and ff06::/16.


Device(config)# ipv6 access-list bidir-grps
Device(config-ipv6-acl)# permit ipv6 any ff05::/16
Device(config-ipv6-acl)# permit ipv6 any ff06::/16
Device(config-ipv6-acl)# exit
Device(config)# ipv6 pim rp-address 200::1 bidir-grps bidir

Related Commands


Command	Description
debug ipv6 pim df-election	Displays debug messages for PIM bidirectional DF-election message processing.
ipv6 access-list	Defines an IPv6 access list and places the router in IPv6 access list configuration mode.
show ipv6 pim df	Displays the DF -election state of each interface for each RP.
show ipv6 pim df winner	Displays the DF-election winner on each interface for each RP.

ipv6 pim rp embedded

To enable embedded rendezvous point (RP) support in IPv6 Protocol Independent Multicast (PIM), use the ipv6 pim rp-embedded command in global configuration mode. To disable embedded RP support, use the

Bias-Free Language

Results

Chapter: IPv6 Commands

IPv6 Commands

clear ipv6 access-list

Syntax Description

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Related Commands

clear ipv6 dhcp

Syntax Description

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clear ipv6 dhcp binding

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clear ipv6 dhcp client

Syntax Description

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clear ipv6 dhcp conflict

Syntax Description

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clear ipv6 dhcp relay binding

Syntax Description

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clear ipv6 eigrp

Syntax Description

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clear ipv6 mfib counters

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clear ipv6 mld counters

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clear ipv6 mld traffic

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clear ipv6 mtu

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