Route IGMP link-local groups

[Lingfeng Xiong]

There are two VLANs in network:

VLAN 30: 192.168.1.0/24

VLAN 40: 192.168.2.0/24

A IGMP multicast group 224.0.0.251 is used for devices in both VLANs.

I try to configure the router to enable the multicast routing, but it seems the router cannot join that multicast group:

ip multicast-routing distributed
3560g-client(config-if)#ip igmp join-group 224.0.0.251
Illegal multicast group address

So is there anyway to make that multicast group routable?

Thank you.

[Akash Agrawal · Accepted solution]

The multicast address, you are trying to join is a link-local multicast address and does not follow normal procedures of join. Any multicast address which belongs to 224.0.0.x is link-local address and few are reserved for protocols which runs over a link, like 224.0.0.9 is used for RIP and 224.0.0.10 is for EIGRP. and similarly 224.0.0.251 is used of mDNS. We will same error message for all these groups.

R6_ASR6(config-if)#ip igmp join-group 224.0.0.9
Illegal multicast group address
R6_ASR6(config-if)#ip igmp join-group 224.0.0.10
Illegal multicast group address
R6_ASR6(config-if)#

http://en.wikipedia.org/wiki/Multicast_address

http://en.wikipedia.org/wiki/Multicast_DNS

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Regards,

Akash

[Trent211111]

Is there a way to make this work? BIAMP has traffic that needs to be sent to endpoints with addresses that reside in the 224.0.0.0/24 range however I can't statically configure it nor does IGMP Snooping process it. So only thing I can think of right now is to disable IGMP Snooping and placing the equipment in its own VLAN and introducing L3 Multicast.