[c-nsp] igmp snooping inside 802.1q trunks

[Francisco Rodrigo Cortinas Maseda]

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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