[Xorp-users] multicast questions!

[Pavlin Radoslavov]

>    we are tring to make our network multicast working. we had test using 
> mtrace, and seems the problme seems happend at our gateway machine. this is 
> our architecture.

FYI, currently XORP doesn't support the IGMP extentions necessary
for mtrace, so mtrace won't be a reliable mechanism to debug the
problem.

> sender machine---gateway (two interfaces)---university router----
> 
> we are running xorp at gateway machines. however, when i run show pim 
> neighbors, it is empty. it seems the router can not find next hop:( any one 

It is odd that "show pim neighbors" doesn't find the university
router as a neighbor, so you need to solve that problem first.
If you run tcpdump on your gateway (on the interface that connects
it to the university router), do you see the PIM Hello packets?
Could be simply that the university router is not configured to run
PIM on that particular subnet?
If you don't see the PIM Hello packets then double-check with your
network admin that PIM is enabled on that interface. Note that the
university router must be running PIM-SMv2; PIM-SMv1 is not
compatible with PIM-SMv2 (for example, if I remember correctly, the
PIM-SMv1 control messages are embedded inside IGMP messages, while
PIM-SMv2 control messages have their own protocol number 103).

> can give us any suggestion? the folloiwng is our xorp configuration file. 
> we do not rellay know whihc RP have to use, it should be the closese one to 
> our gateway? or we should to ask university netwokr people? BTW, it seems 
> the unicast and multicast when we run traceroute, it is using different 
> router just outside our network, will that be a problme?

Your RP-set must be same as the RP-set of the university network, so
you must ask the netadmin folks about that.
If the university network uses a set of static RPs to configure the
RP-set, then you must use the same static RP-set in your
configuration and you should disable the PIM Bootstrap config.

If the university network is using the Bootstrap mechanism to
propagate the RP-set, then you disable the static RPs config, but
you should enable the bootstrap in your config. Furthermore, it
would be safer if you comment-out the cand-bsr and cand-rp setup.

Apart of that your config looks fine, though in any case you must
solve first the neighborhood problem before solving the RP-set
problem.

Pavlin