10-11-2012 01:46 PM - edited 03-07-2019 09:25 AM
Hi,
In the following topology
R1(f0/0)------------(f0/1)SW1(f0/2)------------R2
R1 is configured as host (no ip routing) with ip igmp join 239.10.10.10 on fa0/0 and R2 with ip pim sparse-mode on f0/0. SW1 is a Catalyst 3560 running IOS 12.2(25)SEE4 working at Layer 2 only in this topology (VLAN 1).
I configured SW1 for igmp snooping:
ip igmp snooping
ip igmp snooping vlan 1
Basically, I can see 'snooped' muticast group (via IGMP reports sent by R1)
SW1#sh ip igmp snooping group
Vlan Group Type Version Port List
----------------------------------------------------------------
1 224.0.1.40 igmp v2 Fa0/2
1 239.10.10.10 igmp v2 Fa0/1, Fa0/2
SW1#
SW1#
SW1#
SW1#sh ip igmp snooping mrouter
Vlan ports
---- -----
1 Fa0/2(dynamic)
However CAM table doesn't have the entry for multicast group (Layer 2 GDA)
SW1#sh mac-address-table multicast
Vlan Mac Address Type Ports
---- ----------- ---- -----
SW1#
I believe that it is not expected behavior.....Can you help me ?
Thanks.
Solved! Go to Solution.
10-13-2012 12:49 AM
Hello Carlo,
I believe I have stumbled across the same problem some time ago. According to the Configuration Guide for your IOS, this command is not supported although present in the CLI:
The same document states you should use the show ip igmp snooping groups command to see the multicast groups, although that one will not display the multicast MAC addresses you were looking for.
The IOS you are using is fairly old. If this is a production switch, I would personally recommend upgrading to 12.2(55)SE6. Interestingly enough, however, the show mac address-table multicast command is not supported even in the latest 15.0 IOS. I guess after so many years (the IOS you're running was released sometime in 2008), Cisco software engineers could at least remove the unsupported command instead of leaving it in place - and confusing people.
Best regards,
Peter
10-12-2012 12:43 PM
Just to completeness......I did a ping from R2 to 239.10.10.10 receiving echo replies sent by R1 but no (layer 2) multicast entry in CAM....
Someone can help me ?
10-13-2012 12:49 AM
Hello Carlo,
I believe I have stumbled across the same problem some time ago. According to the Configuration Guide for your IOS, this command is not supported although present in the CLI:
The same document states you should use the show ip igmp snooping groups command to see the multicast groups, although that one will not display the multicast MAC addresses you were looking for.
The IOS you are using is fairly old. If this is a production switch, I would personally recommend upgrading to 12.2(55)SE6. Interestingly enough, however, the show mac address-table multicast command is not supported even in the latest 15.0 IOS. I guess after so many years (the IOS you're running was released sometime in 2008), Cisco software engineers could at least remove the unsupported command instead of leaving it in place - and confusing people.
Best regards,
Peter
10-13-2012 08:15 AM
Thanks !
10-13-2012 08:41 AM
Hi Carlo,
You are welcome. Thank you!
Best regards,
Peter
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