From: Bob Sinclair (bob@bobsinclair.net)
Date: Fri Nov 09 2007 - 14:58:53 ART
nicky noname wrote:
> Hello,
>
> If you disable IGMP snooping on a switch, the switch will still
> forward IGMP messages to and from the host/ router right?
>
Yup!
> The difference being that the IGMP messages will be flooded on the
> vlan. So when the multicast traffic is forwarded to the LAN switch
> from the router, after the router recieves an IGMP join, now will the
> switch drop the traffic because it has no entries in the forwarding
> table, or will it broadcast the traffic out all ports. ( under IGMP
> conditions, only the IGMP traffic goes via the CPU and the pim traffic
> goes to the ports listed in the forwarding table).
>
If you have disabled igmp snooping, then the switch will flood multicast
in the vlan.
However, there is a scenario where you disable IGMP snooping for a vlan
and then statically associate a multicast mac-address on a particular
port or ports. In this circumstance the switch will forward the
multicast to those ports and not flood.
Hth,
--Bob Sinclair CCIE 10427 CCSI 30427 www.netmasterclass.net
This archive was generated by hypermail 2.1.4 : Sat Dec 01 2007 - 06:37:29 ART