- Index
- Preface
- Overview
- Using the Command-Line Interface
- Assigning the Switch IP Address and Default Gateway
- Configuring Cisco IOS Configuration Engine
- Administering the Switch
- Configuring Switch Alarms
- Configuring SDM Templates
- Configuring Switch-Based Authentication
- Configuring IEEE 802.1x Port-Based Authentication
- Configuring Interface Characteristics
- Configuring Command Macros
- Configuring VLANs
- Configuring Private VLANs
- Configuring IEEE 802.1Q and Layer 2 Protocol Tunneling
- Configuring STP
- Configuring MSTP
- Configuring Optional Spanning-Tree Features
- Configuring Resilient Ethernet Protocol
- Configuring Flex Links and the MAC Address-Table Move Update Feature
- Configuring DHCP Features and IP Source Guard
- Configuring Dynamic ARP Inspection
- Configuring IGMP Snooping and MVR
- Configuring Port-Based Traffic Control
- Configuring CDP
- Configuring LLDP and LLDP-MED
- Configuring UDLD
- Configuring SPAN and RSPAN
- Configuring RMON
- Configuring System Message Logging
- Configuring SNMP
- Configuring Embedded Event Manager
- Configuring Network Security with ACLs
- Configuring Control-Plane Security
- Configuring QoS
- Configuring EtherChannels and Link State Tracking
- Configuring IP Unicast Routing
- Configuring IPv6 Unicast Routing
- Configuring IPv6 MLD Snooping
- Configuring IPv6 ACLs
- Configuring HSRP
- Configuring Cisco IOS IP SLAs Operations
- Configuring Enhanced Object Tracking
- Configuring Ethernet OAM, CFM, and E-LMI
- Configuring IP Multicast Routing
- Configuring MSDP
- Troubleshooting
- Configuring Online Diagnostics
- Supported MIBs
- Working with the Cisco IOS File System, Configuration Files, and Software Images
- Unsupported Commands in Cisco IOS Release 12.2(52)SE
Configuring LLDP and LLDP-MED
This chapter describes how to configure the Link Layer Discovery Protocol (LLDP) and LLDP Media Endpoint Discovery (LLDP-MED) on the Cisco ME 3400E switch.
Note For complete syntax and usage information for the commands used in this chapter, see the command reference for this release and the "System Management Commands" section in the Cisco IOS Configuration Fundamentals Command Reference, Release 12.2.
This chapter consists of these sections:
•Understanding LLDP and LLDP-MED
•Configuring LLDP and LLDP-MED
•Monitoring and Maintaining LLDP and LLDP-MED
Understanding LLDP and LLDP-MED
Understanding LLDP
The Cisco Discovery Protocol (CDP) is a device discovery protocol that runs over Layer 2 (the data link layer) on all Cisco-manufactured devices (routers, bridges, access servers, and switches). CDP allows network management applications to automatically discover and learn about other Cisco devices connected to the network.
To support non-Cisco devices and to allow for interoperability between other devices, the switch supports the IEEE 802.1AB Link Layer Discovery Protocol (LLDP). LLDP is a neighbor discovery protocol that is used for network devices to advertise information about themselves to other devices on the network. This protocol runs over the data-link layer, which allows two systems running different network layer protocols to learn about each other.
LLDP supports a set of attributes that it uses to discover neighbor devices. These attributes contain type, length, and value descriptions and are referred to as TLVs. LLDP supported devices can use TLVs to receive and send information to their neighbors. Details such as configuration information, device capabilities, and device identity can be advertised using this protocol.
LLDP is enabled by default on network node interfaces (NNIs). It is disabled on enhanced network interfaces (ENIs), but you can enable it. LLDP is not supported on user network interfaces (UNIs).
The switch supports these basic management TLVs. These are mandatory LLDP TLVs.
•Port description TLV
•System name TLV
•System description
•System capabilities TLV
• Management address TLV
These organizationally specific LLDP TLVs are also advertised to support LLDP-MED.
•Port VLAN ID TLV ((IEEE 802.1 organizationally specific TLVs)
•MAC/PHY configuration/status TLV(IEEE 802.3 organizationally specific TLVs)
Understanding LLDP-MED
LLDP for Media Endpoint Devices (LLDP-MED) is an extension to LLDP that operates between endpoint devices such as IP phones and network devices such as switches. It specifically provides support for voice over IP (VoIP) applications and provides additional TLVs for capabilities discovery, network policy, Power over Ethernet, and inventory management.
LLDP-MED supports these TLVs:
•LLDP-MED capabilities TLV
Allows LLDP-MED endpoints to determine the capabilities that the connected device supports and what capabilities the device has enabled.
•Network policy TLV
Allows both network connectivity devices and endpoints to advertise VLAN configurations and associated Layer 2 and Layer 3 attributes for the specific application on that port. For example, the switch can notify a phone of the VLAN number that it should use. The phone can connect into any switch, obtain its VLAN number, and then start communicating with the call control
•Power management TLV
Enables advanced power management between LLDP-MED endpoint and network connectivity devices. Allows switches and phones to convey power information, such as how the device is powered, power priority, and how much power the device needs.
•Inventory management TLV
Allows an endpoint to transmit detailed inventory information about itself to the switch, including information hardware revision, firmware version, software version, serial number, manufacturer name, model name, and asset ID TLV.
•Location TLV
Provides location information from the switch to the endpoint device. The location TLV can send this information:
–Civic location information
Provides the civic address information and postal information. Examples of civic location information are street address, road name, and postal community name information.
–ELIN location information
Provides the location information of a caller. The location is determined by the Emergency location identifier number (ELIN), which is a phone number that routes an emergency call to the local public safety answering point (PSAP) and which the PSAP can use to call back the emergency caller.
Configuring LLDP and LLDP-MED
•Configuring LLDP Characteristics
•Disabling and Enabling LLDP Globally
•Disabling and Enabling LLDP on an Interface
Default LLDP Configuration
Table 25-1 shows the default LLDP configuration. To change the default settings, use the LLDP global configuration and LLDP interface configuration commands.
Configuring LLDP Characteristics
You can configure the frequency of LLDP updates, the amount of time to hold the information before discarding it, and the initialization delay time. You can also select the LLDP and LLDP-MED TLVs to be sent and received.
Beginning in privileged EXEC mode, follow these steps to configure these characteristics:
Note Steps 2 through 5 are all optional and can be performed in any order.
Use the no form of each of the LLDP commands to return to the default setting.
This example shows how to configure LLDP characteristics.
Switch# configure terminal
Switch(config)# lldp holdtime 120
Switch(config)# lldp reinit 2
Switch(config)# lldp timer 30
Switch(config)# end
For additional LLDP show commands, see the "Monitoring and Maintaining LLDP and LLDP-MED" section.
Disabling and Enabling LLDP Globally
LLDP is disabled globally by default and is enabled on NNIs. It is disabled by default on ENIs, but can be enabled per interface. LLDP is not supported on UNIs.
Beginning in privileged EXEC mode, follow these steps to globally disable LLDP:
|
|
|
---|---|---|
Step 1 |
configure terminal |
Enter global configuration mode. |
Step 2 |
no lldp run |
Disable LLDP. |
Step 3 |
end |
Return to privileged EXEC mode. |
Beginning in privileged EXEC mode, follow these steps to enable LLDP-MED when it has been disabled:
|
|
|
---|---|---|
Step 1 |
configure terminal |
Enter global configuration mode. |
Step 2 |
lldp run |
Enable LLDP. |
Step 3 |
end |
Return to privileged EXEC mode. |
This example shows how to globally disable LLDP.
Switch# configure terminal
Switch(config)# no lldp run
Switch(config)# end
This example shows how to globally enable LLDP.
Switch# configure terminal
Switch(config)# lldp run
Switch(config)# end
Disabling and Enabling LLDP on an Interface
LLDP is disabled by default on all NNIs to send and to receive LLDP information. It is disabled by default on ENIs, but it can be enabled by entering the lldp transmit and lldp receive interface configuration commands. LLDP is not supported on UNIs.
Note If the interface is configured as a tunnel port, LLDP is automatically disabled.
Beginning in privileged EXEC mode, follow these steps to disable LLDP on an interface.
Beginning in privileged EXEC mode, follow these steps to enable LLDP on an interface when it has been disabled:
This example shows how to enable LLDP on an interface.
Switch# configure terminal
Switch(config)# interface GigabitEthernet1/0/1
Switch(config-if)# no shutdown
Switch(config-if)# port-type nni
Switch(config-if)# lldp transmit
Switch(config-if)# lldp receive
Switch(config-if)# end
Configuring LLDP-MED TLVs
By default, the switch only sends LLDP packets until it receives LLDP-MED packets from the end device. It will then send LLDP packets with MED TLVs as well. When the LLDP-MED entry has been aged out, it only sends LLDP packets again.
Using the lldp interface configuration command, you can configure the interface not to send the TLVs listed in Table 25-2.
Beginning in privileged EXEC mode, follow these steps to disable a TLV on an interface:
Beginning in privileged EXEC mode, follow these steps to enable a TLV on an interface:
This example shows how to enable a TLV on an interface when it has been disabled.
Switch# configure terminal
Switch(config)# interface GigabitEthernet1/0/1
Switch(config-if)# lldp med-tlv-select inventory-management
Switch(config-if)# end
Monitoring and Maintaining LLDP and LLDP-MED
To monitor and maintain LLDP and LLDP-MED on your device, perform one or more of these tasks, beginning in privileged EXEC mode.