Re: ICMP snooping on non-routed VLAN

From: rick.fox@tcsny.com
Date: Wed Aug 23 2006 - 19:46:11 ART

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I have a vlan configured on a sup720 without a l3 interface, with servers and receivers sharing that vlan. The hosts do not receive any multicast traffic until I turn off IGMP snooping. I thought it could be a bug, but figured I was forgetting something. Any ideas?

Thanks.
  

-----Original Message-----
From: "Brian McGahan" <bmcgahan@internetworkexpert.com>
Date: Wed, 23 Aug 2006 17:34:03
To:"Rick Fox" <rick.fox@tcsna.com>,<ccielab@groupstudy.com>
Subject: RE: ICMP snooping on non-routed VLAN

        IGMP snooping is a layer 2 function and doesn't require any
layer 3 configuration on the switch performing it. When a host sends an
IGMP join the switch will hear it and add the appropriate multicast MAC
address to the CAM table for that port. What is the specific problem
you are seeing or trying to solve?

Brian McGahan, CCIE #8593
bmcgahan@internetworkexpert.com

Internetwork Expert, Inc.
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> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
Of
> Rick Fox
> Sent: Wednesday, August 23, 2006 11:15 AM
> To: ccielab@groupstudy.com
> Subject: ICMP snooping on non-routed VLAN
>
> Can IGMP work on a vlan without a routed interface?
>
> Lets say you have multiple multicast servers and receivers sharing a
vlan
> that
> is not routed. With IGMP snooping enabled (default), the recievers do
not
> receive any muticast traffic. When IGMP snooping is disabled, the
> receivers
> receive all the multicast traffic. This can be undesirable as the
> receivers
> should only receive multicast on the groups they join.
>
> There is a command IGMP snooping querier, but this requires creating a
> vlan
> interface and putting an ip address on it.
>
> Any other suggestions?
>
> Thanks.
>
>

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