[c-nsp] Multicast Issue

[Rodney Dunn]

Try this.

On the interface facing the server configure:

ip igmp join-group 224.0.1.55 and from the client
ping 224.0.1.55 and see if you get a response.

You don't want to use join-group because that makes the
rotuer a receiver but at least this would tell you if the
traffic is getting to the 65xx.

You really want the ip igmp static-group on the vlan towards
the server like others have said but the join-group might help
the debugging a little.

Just test with pings from the client. You could put a router
on the same vlan and configure it's interface with join-group
to test the mcast connectivity through the 65xx.

Rodney


On Thu, Apr 27, 2006 at 08:35:30AM -0600, John Neiberger wrote:
> >In any case, the tools to use now would be sh int cou on gig 4/16 to 
> >see if mcast out is incrementing on the 6k (hopefully it's a fairly 
> >high rate source, if not, then you won't be able to tell), and if 
> >mcast in is incrementing on the 2950.
> >
> >You can also always try a span session to a sniffer of gig 4/16 in 
> >the tx direction to see if the packets are going out.
> 
> Unfortunately, this application sends a single multicast packet. It
> will send up to six if there is no response. This is just a horribly
> designed application. Get this:
> 
> The client begins talking to the server via TCP, so it already
> obviously knows the server's IP address. After it's been talking to the
> server for a few seconds (a couple hundred packets) the client sends a
> single multicast packet to 224.0.1.55. This is some sort of server
> location mechanism. But it shouldn't be necessary because the client
> obviously already knows the IP address of the server. To make this even
> more colossally dumb, the IP address of the server is IN THE DATA
> PORTION OF THE MULTICAST PACKET! If the client does not receive a
> unicast response to this multicast packet, the client can't connect, at
> least from the user's perspective. Really bad design because that means
> that the server doesn't use IGMP to join the group, which means it has
> to be on the same LAN as all of the clients. I'm just trying to find a
> way to make it work for now until we can talk to the developers of the
> application.
> 
> Thanks!
> John
> --
> _______________________________________________
> 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/