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Lingfeng Xiong
Beginner

Route IGMP link-local groups

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.

Regards, Lingfeng Xiong
1 ACCEPTED SOLUTION

Accepted Solutions
Akash Agrawal
Cisco Employee

 

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

 

--- Please don't forget to rate helpful posts -----

Regards,

Akash

View solution in original post

1 REPLY 1
Akash Agrawal
Cisco Employee

 

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

 

--- Please don't forget to rate helpful posts -----

Regards,

Akash

View solution in original post