IGMP snooping on 6509

[netsquant]

When igmp snooping is applied the interface that sends multicast packets out the job fails after a few minutes. If IGMP is turned off the job passes but multicast hammers the entire network so i need it working. Any suggestions.

[Jon Marshall]

Okay let us know how you get on.

One other thing. You don't have any traffic storm control configured on your 6500 switchports do you ?

Jon

[netsquant]

no.

[Jon Marshall]

Sorry, just reread that. The 6500 doesn't support CGMP at Layer 2 -

http://www.cisco.com/en/US/tech/tk828/technologies_tech_note09186a0080122a70.shtml

Jon

[netsquant]

i just saw that myself only 4000 and 5000 series.

[Jon Marshall]

So when the job crashes does the interface stay up and passing other traffic. Do you get any logs from the job as to why it failed.

You could try upgrading your software but i'm not convinced that will make any difference.

Jon

[Jon Marshall]

The only other thing that springs to mind is that you could statically map the multicast address to the relevant ports on the switch. If the intended destinations are always the same this might be a bit of work at the start.

But obviously if the membership is dynamic this is no good to you.

Jon

[netsquant]

the server guys who are running the multicast jobs think it may have something to do with the vm enviroment.

I will keep you posted.

Thank you.

[CriscoSystems]

Shane, IGMP and CGMP are exclusive of each other. If you've got one configured then you can't run the other. So if IGMP is what you really want to use, CGMP can't be the "missing piece."

An IGMP switch has the ability to read the L3 packet inside the frame and to map which port it's using to get to the mcast group member. A switch that can't (or won't) do this can use CGMP. In CGMP, the switch relies on a PIM-enabled router upstream from the multicast members. The router informs the switch of the unicast MAC addresses of all the mcast group members it knows about, the switch then maps those MAC addresses (and corresponding exit ports) to the relevant multicast address(es).

I don't know enough about your setup to know why IGMP is failing, but if you've got CGMP-compatible equipment, it's worth a shot to shut down IGMP and see what luck you have with CGMP.

Hope to help, and please remember to rate helpful posts.

-- stuey