3com 8807 User Guide

C

HAPTER

 41: C

OMMON

 M

ULTICAST

 C

ONFIGURATION

After the above configuration, execute display command in any view to display 
the running of the multicast configuration, and to verify the effect of the 
configuration.

Execute debugging command in user view for the debugging of multicast.

The multicast routing tables can be layered as follows:

■

Each multicast routing protocol has a multicast routing table of itself.

■

All the multicast routing tables can be summarized into the multicast kernel 
routing tables.

■

The multicast kernel routing tables should keep consistent with the multicast 
forwarding tables which actually control the forwarding of the multicast data 
packets.

The multicast forwarding tables are mainly used for debugging. Usually, users can 
view the multicast kernel routing tables to get the required information.

Table 431   Display and Debug Common Multicast Configuration

Display the multicast 
routing table 

display multicast routing-table [ group-address [ mask { mask 
| mask-length } ] | source-address [ mask { mask | mask-length } ] 
| incoming-interface { vlan-interface vlan-interface-number | 
register } ]* 

Display the multicast 
forwarding table 

display multicast forwarding-table [ group-address [ mask { 
mask | mask-length } ] | source-address [ mask { mask | 
mask-length } ] | incoming-interface { interface-type 
interface-number | null NULL-interface- number | register } ]* 

View port-specific multicast 
forwarding table 
ninformation 

display mpm forwarding-table [ group-address | 
source-address ] 

View IP multicast group and 
MAC multicast group 
information of all VLANs or 
a specific VLAN 

display mpm group [ vlan vlan-id [ ip-address ] ] 

Enable multicast packet 
forwarding debugging 

debugging multicast forwarding 

Disable multicast packet 
forwarding debugging 

undo debugging multicast forwarding 

Enable multicast 
forwarding status 
debugging 

debugging multicast status-forwarding 

Disable multicast 
forwarding status 
debugging 

undo debugging multicast status-forwarding 

Enable multicast kernel 
routing debugging 

debugging multicast kernel-routing 

Disable multicast kernel 
routing debugging