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