[c-nsp] igmp snooping inside 802.1q trunks

[Tim Stevenson]

Huh? There is no default "flooding mode" state. IGMP snooping is on 
by default on the 6500, and multicast is constrained as long as there 
is a querier (provided your multicast groups don't map to 0100.5e00.00xx).

Tim

At 06:37 AM 2/1/2006, Francisco Rodrigo Cortinas Maseda submitted:
>The swich is working on "Flooding" mode (default state on Cisco
>switches). You should go to "Non-flooding" mode. If not, IGMP snooping
>has no effect.
>
>Regards.
>
>-----Mensaje original-----
>De: cisco-nsp-bounces at puck.nether.net
>[mailto:cisco-nsp-bounces at puck.nether.net] En nombre de Tim Stevenson
>Enviado el: martes 31 de enero de 2006 19:28
>Para: Vladimir Ivashchenko
>CC: cisco-nsp at puck.nether.net
>Asunto: Re: [c-nsp] igmp snooping inside 802.1q trunks
>
>
>Are you seeing snooping entries for the MAC? 0100.5e40.00xx (sh mac-
>multi igmp) If so, what is the port mask? You are sure it is
>239.192.0.x & not 239.128.0.x? The latter would map to a reserved
>range MAC, & we won't install a snooping mac entry for it, it will
>flood....
>
>Tim
>
>At 10:19 AM 1/31/2006, Vladimir Ivashchenko submitted:
>
> >239.192.0.x
> >
> >On Mon, 2006-01-30 at 13:40 -0800, Tim Stevenson wrote:
> > > What group(s) are you sending to?
> > >
> > > Tim
> > >
> > > At 01:28 PM 1/30/2006, Vladimir Ivashchenko murmered:
> > > > > > The problem is that 6500 seems to unconditionally forward
> > all multicast
> > > > > > traffic to all trunk ports even if there are no receivers
> > > > > > there. E.g. "show mac-address-table multicast" does not show
> > > > > > any entries for that port, however it still receives all
> > > > > > multicast traffic.
> > > > > >
> > > > > > Any ideas?
> > > > >
> > > > > The 6500 is going to forward multicast traffic to any routers it
>
> > > > > learns about. Does a "show multicast router" on the 6500 list
> > > > > all the trunk ports?
> > > >
> > > >I checked it (using IOS's sh ip igmp snooping mrouter), only one
> > > >port there as expected.
> > > >
> > > >--
> > > >Best Regards
> > > >Vladimir Ivashchenko
> > > >Chief Technology Officer
> > > >Thunderworx, Cyprus - www.thunderworx.com
> > > >_______________________________________________
> > > >cisco-nsp mailing list  cisco-nsp at puck.nether.net
> > > >https://puck.nether.net/mailman/listinfo/cisco-nsp
> > > >archive at http://puck.nether.net/pipermail/cisco-nsp/
> > >
> > >
> > >
> > > Tim Stevenson, tstevens at cisco.com
> > > Routing & Switching CCIE #5561
> > > Technical Marketing Engineer, Catalyst 6500
> > > Cisco Systems, http://www.cisco.com
> > > IP Phone: 408-526-6759
> > > ********************************************************
> > > The contents of this message may be *Cisco Confidential* and are
> > > intended for the specified recipients only.
> >--
> >Best Regards,
> >Vladimir Ivashchenko
> >Chief Technology Officer
> >Thunderworx Cyprus - www.thunderworx.com
>
>
>
>Tim Stevenson, tstevens at cisco.com
>Routing & Switching CCIE #5561
>Technical Marketing Engineer, Catalyst 6500
>Cisco Systems, http://www.cisco.com
>IP Phone: 408-526-6759
>********************************************************
>The contents of this message may be *Cisco Confidential*
>and are intended for the specified recipients only.
>_______________________________________________
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Tim Stevenson, tstevens at cisco.com
Routing & Switching CCIE #5561
Technical Marketing Engineer, Catalyst 6500
Cisco Systems, http://www.cisco.com
IP Phone: 408-526-6759
********************************************************
The contents of this message may be *Cisco Confidential*
and are intended for the specified recipients only.