Examples
The following example shows the sample output from the show ip mroute command:
Device# show ip mroute
IP Multicast Routing Table
Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C - Connected,
L - Local, P - Pruned, R - RP-bit set, F - Register flag,
T - SPT-bit set, J - Join SPT, M - MSDP created entry,
X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement,
U - URD, I - Received Source Specific Host Report, Z - Multicast Tunnel,
Y - Joined MDT-data group, y - Sending to MDT-data group
Timers: Uptime/Expires
Interface state: Interface, Next-Hop, State/Mode
(*, 224.0.255.3), uptime 5:29:15, RP is 192.168.37.2, flags: SC
Incoming interface: Tunnel0, RPF neighbor 10.3.35.1, Dvmrp
Outgoing interface list:
Ethernet0, Forward/Sparse, 5:29:15/0:02:57
(192.168.46.0/24, 224.0.255.3), uptime 5:29:15, expires 0:02:59, flags: C
Incoming interface: Tunnel0, RPF neighbor 10.3.35.1
Outgoing interface list:
Ethernet0, Forward/Sparse, 5:29:15/0:02:57
The following is sample output from the show ip mroute command with the IP multicast group address 232.6.6.6 specified:
Device# show ip mroute 232.6.6.6
IP Multicast Routing Table
Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C - Connected,
L - Local, P - Pruned, R - RP-bit set, F - Register flag,
T - SPT-bit set, J - Join SPT, M - MSDP created entry,
X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement,
U - URD, I - Received Source Specific Host Report, Z - Multicast Tunnel,
Y - Joined MDT-data group, y - Sending to MDT-data group
Outgoing interface flags:H - Hardware switched
Timers:Uptime/Expires
Interface state:Interface, Next-Hop or VCD, State/Mode
(*, 232.6.6.6), 00:01:20/00:02:59, RP 224.0.0.0, flags:sSJP
Incoming interface:Null, RPF nbr 224.0.0.0
Outgoing interface list:Null
(10.2.2.2, 232.6.6.6), 00:01:20/00:02:59, flags:CTI
Incoming interface:Ethernet3/3, RPF nbr 224.0.0.0
Outgoing interface list:
Ethernet3/1, Forward/Sparse-Dense, 00:00:36/00:02:35
The following example shows the sample output from the show ip mroute vrf * command:
Device# show ip mroute vrf *
IP Multicast Routing Table
Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C - Connected,
L - Local, P - Pruned, R - RP-bit set, F - Register flag,
T - SPT-bit set, J - Join SPT, M - MSDP created entry, E - Extranet,
X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement,
U - URD, I - Received Source Specific Host Report,
Z - Multicast Tunnel, z - MDT-data group sender,
Y - Joined MDT-data group, y - Sending to MDT-data group,
G - Received BGP C-Mroute, g - Sent BGP C-Mroute,
N - Received BGP Shared-Tree Prune, n - BGP C-Mroute suppressed,
Q - Received BGP S-A Route, q - Sent BGP S-A Route,
V - RD & Vector, v - Vector, p - PIM Joins on route,
x - VxLAN group, c - PFP-SA cache created entry,
* - determined by Assert, # - iif-starg configured on rpf intf,
e - encap-helper tunnel flag, l - LISP Decap Refcnt Contributor
Outgoing interface flags: H - Hardware switched, A - Assert winner, p - PIM Join
t - LISP transit group
Timers: Uptime/Expires
Interface state: Interface, Next-Hop or VCD, State/Mode
VRF IPv4 default
(100.99.99.99, 232.101.100.138), 1w1d/00:02:58, flags: sT
Incoming interface: Null0, RPF nbr 0.0.0.0
Outgoing interface list:
Ethernet0/1, Forward/Sparse, 1w1d/00:02:58, flags:
(100.99.99.99, 232.101.100.157), 1w1d/00:03:27, flags: sT
Incoming interface: Null0, RPF nbr 0.0.0.0
Outgoing interface list:
Ethernet0/1, Forward/Sparse, 1w1d/00:03:27, flags:
(100.88.88.88, 232.134.100.138), 1w1d/00:01:54, flags: sT
Incoming interface: Ethernet0/0, RPF nbr 40.10.2.1
Outgoing interface list:
Null0, Forward/Dense, 1w1d/stopped, flags:
(100.88.88.88, 232.134.100.157), 1w1d/00:01:54, flags: sT
Incoming interface: Ethernet0/0, RPF nbr 40.10.2.1
Outgoing interface list:
Null0, Forward/Dense, 1w1d/stopped, flags:
(*, 224.0.1.40), 1w1d/00:02:53, RP 0.0.0.0, flags: DP
Incoming interface: Null, RPF nbr 0.0.0.0
Outgoing interface list: Null
VRF red
(*, 225.64.64.1), 1w1d/00:03:23, RP 5.5.5.5, flags: Sl
Incoming interface: LISP0.101, RPF nbr 100.88.88.88
Outgoing interface list:
LISP0.101, (100.99.99.99, 232.101.100.157), Forward/Sparse, 1w1d/stopped, flags:
(*, 225.32.32.32), 1w1d/00:03:05, RP 5.5.5.5, flags: Sl
Incoming interface: LISP0.101, RPF nbr 100.88.88.88
Outgoing interface list:
LISP0.101, (100.99.99.99, 232.101.100.138), Forward/Sparse, 1w1d/stopped, flags:
Table 1. show ip mroute Field Descriptions
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Field
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Description
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Flags:
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Provides information about the entry.
-
D--Dense. Entry is operating in dense mode.
-
S--Sparse. Entry is operating in sparse mode.
-
B--Bidir Group. Indicates that a multicast group is operating in bidirectional mode.
-
s--SSM Group. Indicates that a multicast group is within the SSM range of IP addresses. This flag is reset if the SSM range
changes.
-
C--Connected. A member of the multicast group is present on the directly connected interface.
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Flags: (continued)
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-
L--Local. The device itself is a member of the multicast group. Groups are joined locally by the ip
igmp
join-group command (for the configured group), the
ip
sap
listen command (for the well-known session directory groups), and rendezvous point (RP) mapping (for the well-known groups 224.0.1.39
and 224.0.1.40). Locally joined groups are not fast switched.
-
P--Pruned. Route has been pruned. The Cisco IOS software keeps this information so that a downstream member can join the
source.
-
R--RP-bit set. Indicates that the (S, G) entry is pointing toward the RP. This flag typically indicates a prune state along
the shared tree for a particular source.
-
F--Register flag. Indicates that the software is registering for a multicast source.
-
T--SPT-bit set. Indicates that packets have been received on the shortest path source tree.
-
J--Join SPT. For (*, G) entries, indicates that the rate of traffic flowing down the shared tree is exceeding the SPT-Threshold
set for the group. (The default SPT-Threshold setting is 0 kbps.) When the J - Join shortest path tree (SPT) flag is set,
the next (S, G) packet received down the shared tree triggers an (S, G) join in the direction of the source, thereby causing
the device to join the source tree.
For (S, G) entries, indicates that the entry was created because the SPT-Threshold for the group was exceeded. When the
J - Join SPT flag is set for (S, G) entries, the device monitors the traffic rate on the source tree and attempts to switch
back to the shared tree for this source if the traffic rate on the source tree falls below the SPT-Threshold of the group
for more than 1 minute.
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Note
|
The device measures the traffic rate on the shared tree and compares the measured rate to the SPT-Threshold of the group
once every second. If the traffic rate exceeds the SPT-Threshold, the J - Join SPT flag is set on the (*, G) entry until the
next measurement of the traffic rate. The flag is cleared when the next packet arrives on the shared tree and a new measurement
interval is started. If the default SPT-Threshold value of 0 kbps is used for the group, the J - Join SPT flag is always set
on (*, G) entries and is never cleared. When the default SPT-Threshold value is used, the device immediately switches to the
shortest path source tree when traffic from a new source is received.
|
-
M--MSDP created entry. Indicates that a (*, G) entry was learned through a Multicast Source Discovery Protocol (MSDP) peer.
This flag is applicable only for an RP running MSDP.
-
E--Extranet source mroute entry. Indicates that a (*, G) or (S, G) entry in the VRF routing table is a source Multicast VRF
(MVRF) entry and has extranet receiver MVRF entries linked to it.
-
X--Proxy Join Timer Running. Indicates that the proxy join timer is running. This flag is set only for (S, G) entries of
an RP or “turnaround” device. A “turnaround” device is located at the intersection of a shared path (*, G) tree and the shortest
path from the source to the RP.
-
A--Candidate for MSDP Advertisement. Indicates that an (S, G) entry was advertised through an MSDP peer. This flag is applicable
only for an RP running MSDP.
-
U--URD. Indicates that a URL Rendezvous Directory (URD) channel subscription report was received for the (S, G) entry.
-
I--Received Source Specific Host Report. Indicates that an (S, G) entry was created by an (S, G) report. This (S, G) report
could have been created by Internet Group Management Protocol Version 3 (IGMPv3), URD, or IGMP v3lite. This flag is set only
on the designated device (DR).
-
Z--Multicast Tunnel. Indicates that this entry is an IP multicast group that belongs to the Multicast Distribution Tree (MDT)
tunnel. All packets received for this IP multicast state are sent to the MDT tunnel for decapsulation.
-
Y--Joined MDT-data group. Indicates that the traffic was received through an MDT tunnel that was set up specifically for
this source and group. This flag is set in Virtual Private Network (VPN) mroute tables only.
-
y--Sending to MDT-data group. Indicates that the traffic was sent through an MDT tunnel that was set up specifically for
this source and group. This flag is set in VPN mroute tables only.
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Outgoing interface flags:
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Provides information about the entry.
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Timers:Uptime/Expires
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“Uptime” indicates per interface how long (in hours, minutes, and seconds) the entry has been in the IP multicast routing
table. “Expires” indicates per interface how long (in hours, minutes, and seconds) until the entry will be removed from the
IP multicast routing table.
|
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Interface state:
|
Indicates the state of the incoming or outgoing interface.
-
Interface. Indicates the type and number of the interface listed in the incoming or outgoing interface list.
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Next-Hop or VCD. “Next-hop” specifies the IP address of the downstream neighbor. “VCD” specifies the virtual circuit descriptor
number. “VCD0” means the group is using the static map virtual circuit.
-
State/Mode. “State” indicates that packets will either be forwarded, pruned, or null on the interface depending on whether
there are restrictions due to access lists or a time-to-live (TTL) threshold. “Mode” indicates whether the interface is operating
in dense, sparse, or sparse-dense mode.
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(*, 224.0.255.1) and (192.168.37.100, 224.0.255.1)
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Entry in the IP multicast routing table. The entry consists of the IP address of the source followed by the IP address of
the multicast group. An asterisk (*) in place of the source device indicates all sources.
Entries in the first format are referred to as (*, G) or “star comma G” entries. Entries in the second format are referred
to as (S, G) or “S comma G” entries. (*, G) entries are used to build (S, G) entries.
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RP
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Address of the RP device. For devices and access servers operating in sparse mode, this address is always 224.0.0.0.
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flags:
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Information about the entry.
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Incoming interface:
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Expected interface for a multicast packet from the source. If the packet is not received on this interface, it is discarded.
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RPF neighbor or RPF nbr
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IP address of the upstream device to the source. Tunneling indicates that this device is sending data to the RP encapsulated
in register packets. The hexadecimal number in parentheses indicates to which RP it is registering. Each bit indicates a different
RP if multiple RPs per group are used. If an asterisk (*) appears after the IP address in this field, the RPF neighbor has
been learned through an assert.
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Outgoing interface list:
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Interfaces through which packets will be forwarded.
When the ip
pim
nbma-mode command is enabled on the interface, the IP address of the Protocol Independent Multicast (PIM) neighbor is also displayed.
The Blocked keyword will be displayed in the output if the interface is blocked (denied) by RSVP mulicast CAC.
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