[c-nsp] multicast on layer 2

[Tantsura, Jeff]

Tim,

Does this mean that layer 3 interface always must be present?

Jeff

-----Original Message-----
From: Tim Stevenson [mailto:tstevens at cisco.com] 
Sent: 27 June 2005 17:14
To: Tantsura, Jeff; 'Andrew K Ho'
Cc: cisco-nsp at puck.nether.net
Subject: RE: [c-nsp] multicast on layer 2

Enabling PIM enables IGMP, and the router starts sending periodic General 
Queries. There is no way to enable queries w/o enabling PIM. But, as long 
as "ip multicast-routing" is not in the config, you won't L3 switch the 
multicast.

The other options are as I described. You need a querier in the VLAN, or 
you need to disable snooping & flood on all ports.

Tim

At 07:14 AM 6/27/2005, Tantsura, Jeff observed:
>Presence of layer 3 interface on the same VLAN could change the picture.
>Since sources and receivers would register on it enabling PIM could help.
>Could you test it with PIM enabled and let me know whether it helped?
>
>BTW without IGMP snooping there's no point in using multicast, in fact
>switch will broadcast every multicast frame.
>
>--
>Jeff Tantsura  CCIE# 11416
>Senior IP Network Engineer
>
>
>-----Original Message-----
>From: Andrew K Ho [mailto:aho at yorku.ca]
>Sent: 27 June 2005 15:28
>To: Tim Stevenson
>Cc: cisco-nsp at puck.nether.net
>Subject: Re: [c-nsp] multicast on layer 2
>
>I'm afraid this setup is just on layer 2.  Two directly connected switches
>on trunk links, both allowing the same vlan.  Although there is a vlan
>interface on the router, the traffic shouldn't be processed by the router.
>  Hence no need for PIM (as Jeff pointed out).  For reasons I can't fathom,
>IGMP snooping is always off on our network, and as our planners want it to
>remain this way, the IGMP querier feature would not make any difference.
>
>Thx for all the replies.
>
>Andy
>
>
>
>Tim Stevenson <tstevens at cisco.com>
>06/24/2005 03:57 PM
>
>To
>Andrew K Ho <aho at yorku.ca>, cisco-nsp at puck.nether.net
>cc
>
>Subject
>Re: [c-nsp] multicast on layer 2
>
>
>
>
>
>
>You might try:
>* enabling PIM on an SVI in that VLAN
>* enabling the IGMP querier feature
>* disabling IGMP snooping (not really advisable, floods to all ports)
>
>For IGMP snooping to work properly, an IGMP querier MUST be present in the
>
>VLAN.
>
>See:
>http://www.cisco.com/warp/public/473/38.html
>
>HTH,
>Tim
>
>At 12:28 PM 6/24/2005, Andrew K Ho declared:
> >Hi, I was hoping someone could help me on this.
> >
> >I'm having a problem with an application on our network called Drive
>Image
> >Pro (used to push pc images to build client machines), which purports to
> >be a multicast application, but which is only being used at layer 2 as
>all
> >traffic btn server and client  is contained in 1 vlan, hence is working
> >essentially the same as broadcasts.  Howevever, the server and client
>send
> >multicast packets to a multicast address to send packets.
> >
> >The server is connected to  Model / Serial cisco WS-C6509  OS / Version
> >ios / 12.1(22)E2 on a 100m connection and the client is connected to a
> >100m port on  Model / Serial cisco 4506  OS / Version ios / 12.2(20)EW .
> >They are connected directly through a trunk link, running at gig on
>fiber.
> >  The server and  client are pingable from either side so there is no
> >reachability issue.
> >
> >If the server and client are both on the 4506, it works fine, but won't
> >work if connected as described above.  There are no configs affecting
> >multicast packets.
> >
> >Has anyone come across a problem like this or have any clue as to why it
> >may not be working?
> >
> >Thx in advance
> >
> >Andy
> >_______________________________________________
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> >https://puck.nether.net/mailman/listinfo/cisco-nsp
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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.
>
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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.