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Identifying Multicast Groups

jeff-krauss
Level 1
Level 1

When I perform a "show ip igmp groups" on my Catalyst 4507, I see the following:

Cat4507R_Lab_Admn#sh ip igmp groups

IGMP Connected Group Membership

Group Address Interface Uptime Expires Last Reporter

224.0.1.40 Vlan101 2w3d 00:02:22 10.1.101.254

239.255.219.45 Vlan101 6d11h 00:02:27 10.1.101.120

224.0.1.60 Vlan101 2w3d 00:02:25 10.1.101.199

225.78.86.83 Vlan101 1w0d 00:02:31 10.1.101.148

239.255.255.250 Vlan101 2w3d 00:02:22 10.1.101.183

239.255.255.253 Vlan101 2w3d 00:02:30 10.1.101.125

While I understand that most of these are reserved or local scoped multicast group addresses, I have not been able to identify what most of them actually are except for:

224.0.1.40 cisco-rp-discovery

224.0.1.60 says hp-device-disc, but that's not really what it is.

Would be grateful for feedback/ideas!

Thank you!

1 Reply 1

rais
Level 7
Level 7

RFC 2365 reserves 239.0.0.0 space as administratively scoped. Just like RFC 1918. You can use it for any purpose.

IANA list for reserved multicast addresses can be found at:

http://www.iana.org/assignments/multicast-addresses

Thanks.