[c-nsp] C3845 not processing IGMP reports

[Collins, Richard (SNL US)]

It might be useful to see additional information such as:

c3845#show ip igmp interface gi0/1.180

c3845#show ip igmp groups

and maybe a debug of one of the host multicast groups:

c3845#debug ip igmp x.x.x.x

-Rich

>Message: 2
>Date: Wed, 27 Jun 2007 15:55:04 +0300
>From: Matti Saarinen <mjsaarin at cc.helsinki.fi>
>Subject: [c-nsp] C3845 not processing IGMP reports
>To: cisco-nsp at puck.nether.net
>Message-ID: <yq3jk5tpsgk7.fsf at lagavulin.it.helsinki.fi>
>Content-Type: text/plain; charset=us-ascii
>
>
>What could be causing the following problem with Cisco 3845 and IGMP
>reports?
>
>We've got a 3845 running 12.4(13a) which appears not to process IGMP
>reports which are sent to it. The host is sendind IGMP reports for a
>group (tcpdump shows them) but the 3845 doesn't see them according to
>the output from debug ip igmp. The IGMP queries sent by the router are
>seen by the host. Also, when the host sends an IGMP leave packet the
>router sees it. 
>
>The subnet the host belongs to is connected to a GE sub interface which
>is dot1q tagged. There is a HP 5308 between the host and 3845 but it
>isn't processing IGMP at all.
>
>Below is some config info:
>
>c3845#show run int gi0/1.180
>[...]
>interface GigabitEthernet0/1.180
> description nnnn
> encapsulation dot1Q 180
> ip address x.x.x.x
> ip helper-address y.y.y.y
> ip helper-address z.z.z.z
> ip pim sparse-mode
>end
>
>c3845#sh ip multicast interface gi0/1.180
>GigabitEthernet0/1.180 is up, line protocol is up
>  Internet address is x.x.x.x/24
>  Multicast routing: enabled
>  Multicast switching: fast
>  Multicast packets in/out: 4/92094
>  Multicast TTL threshold: 0
>  Multicast Tagswitching: disabled
>
>
>Cheers,
>
>-- 
>- Matti -
>
>