[Xorp-users] multicast questions!

Troy Benjegerdes hozer@hozed.org
Mon, 30 Jan 2006 17:50:38 -0600


On Mon, Jan 30, 2006 at 12:35:35PM -0800, Pavlin Radoslavov wrote:
> >     thakn you so much!! we had contacted the university netwokr people and 
> > didi some configuration. it seem now we can see neighbors. and internal 
> > mlticast seems wokr fine. we can see our machines from beacon. the attached 
> > file is some tests using xorpsh. however, we try to connect to Access Grid 
> > venue server, we still can not see other people login from other network. 
> > is there any standard procedure we can make sure our multicast is wokring 
> > propertly?
> 
> Sorry, I am not familiar with the Access Grid venue server and how
> it uses multicast so I cannot provide you specific details how to
> fix the problem.
> 
> To test the multicast delivery only, start a test sender and a test
> receiver on the hosts that will be a multicast sender/receiver
> respectively within the Access Grid framework. I'd recommend to use
> the MGEN software for your testing:
> http://tang.itd.nrl.navy.mil/5522/mgen/mgen_index.html

You will want to use the Multicast Beacon at your site and the remote
site(s) to test multicast connectivity for Access Grid.

http://dast.nlanr.net/Projects/Beacon/

You'll want to make sure that your beacon is seeing packets from the
remote site's beacon and vice versa. If the beacon is working, you will
probably want to talk to a more access-grid specific group to figure out
what else is wrong.

FYI, at http://scl.ameslab.gov, we've been running a OpenBSD box as a
multicast router with XORP for the last year or so with no real
problems. Once you get it set up and figure out how to debug multicast,
it all just works. 

I suppose we've a victim of our own success because since it's been
working, I've forgotten all the steps needed to set it up ;)

My first piece of advice though, is get friendly with the operator of
your upstream router, and see if there is a way you can get command line
access on it to run multicast debugging tools, and show the upstream
router's PIM status and multicast forwarding table.