This post is more than 5 years old
3 Posts
0
32559
N3000 (6.1.1.7) igmp snooping issue
G'day!
I'm setting up a new N3048P switch and having a weird issue with multicast packets being flooded to all ports in the Vlan ONLY when there is nobody joined to that multicast group, ie. 'show ip igmp snooping group' shows that the table is empty 'There are currently no entries in the table.'
If there is one or more hosts that joined the multicast group the IGMP Snooping works as expected - no flooding - multicast packets arrive only on interfaces where hosts have 'asked' for it and are in the IGMP Snooping table as per 'show ip igmp snooping group' command output.
Has anyone seen this before? Is this a normal behaviour?
He11o
3 Posts
1
October 26th, 2014 17:00
After reading the bible (tools.ietf.org/.../rfc4541) this is the expected behaviour of an "unregistered packet" as per paragraph 3 of tools.ietf.org/.../rfc4541
Anonymous
5 Practitioner
5 Practitioner
•
274.2K Posts
0
October 20th, 2014 08:00
My understanding, is that you will typically see this behavior when a multicast server is plugged into a L2 switch, with no multicast router set.
does the multicast server plug into the 3048? Is the 3048 setup at the multicast router, or is it just in L2 mode?
If you are able to post up the running config, we can help look through it.
Anonymous
5 Practitioner
5 Practitioner
•
274.2K Posts
0
October 27th, 2014 06:00
Good info to have, thanks for sharing.