Listing basic route data for active multicast groups

Syntax:


show ip mroute

Lists the following data for all VLANs actively forwarding multicast traffic, or for VLANs receiving registered but non-forwarding traffic on an RP.

Group Address

The multicast group IP address of the specific flow (source-group pair.)

Source Address

The unicast address of the flow's source.

Neighbor

The IP address of the upstream multicast router interface (VLAN) from which the multicast traffic is coming. A blank field for a given multicast group indicates that the multicast server is directly connected to the router.

VLAN

The interface on which the router received the multicast flow.

The following examples display the show ip mroute output illustrating three different cases:

Showing source-DR PIM router

Source-DR PIM router. A flow's Neighbor field is not empty for a PIM Router with a directly connected source.

switch#  sh ip pim mroute
 
 IP Multicast Route Entry
 
  Group Address  : 226.94.2.2
  Source Address : 70.70.70.10
  Neighbor       : 70.70.70.10
  VLAN           : 70
  Up Time (sec)     : 72
  Expire Time (sec) : 292
 
  Multicast Routing Protocol : PIM-SM
  Unicast Routing Protocol   : connected

Showing intermediate PIM router

Flows show their adjacent PIM neighbor towards the source.

switch(config)# show ip mroute
 IP Multicast Route Entries
 Total number of entries : 2
 Group Address   Source Address  Neighbor         VLAN
 --------------- --------------- ---------------- ----
 239.255.12.42   10.0.0.10       20.0.0.1         20
 239.255.255.255 10.0.0.10       20.0.0.1         20

Showing new RP special case

RP special case: When run on a RP, registered but non-forwarding flows are displayed without a neighbor value. This is identical in appearance to a direct-connected source, but on an RP this indicates the unique registered, non-forwarding condition.

switch(config)# show ip mroute
 IP Multicast Route Entries
 Total number of entries : 2
 Group Address   Source Address  Neighbor         VLAN
 --------------- --------------- ---------------- ----
 239.255.12.42   10.0.0.10       20.0.0.1         20
 239.255.5.20    10.0.0.10                        20