[c-nsp] multicast on layer 2

[Andrew K Ho]

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
>_______________________________________________
>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.