[Xorp-users] How to choose a good cand-rp-by-vif-name ?

[Pavlin Radoslavov]

Ben Greear <greearb at candelatech.com> wrote:

> Pavlin Radoslavov wrote:
> > Ben Greear <greearb at candelatech.com> wrote:
> >
> >
> >> I'm working on configuring Xorp with multicast support.
> >>
> >> The bootstrap configuration wants a candidate VIF.
> >>
> >> Supposing there are lots of interfaces, how does one decide which one to use for
> >> the cand-rp-by-vif-name?
> >>
> >
> > The primary IP address of the chosen vif must be reachable
> > (routable) by all other PIM-SM routers in your network.
> >
> > Regards,
> > Pavlin
> >
> I don't think my 'cand-rp' is working properly.  Should I see any sort of
> broadcasts/multicasts on
> the interface chosen for cand-rp?  How about other interfaces in the router?

If the Bootstrap Router (BSR) election has completed, you should see
periodic unicast PIM Cand-RP messages from this router to the BSR.
Those messages should come on the interface used to route unicast
traffic toward the BSR. The Cand-RP address inside the message
should be the primary address of the interface selected by the
cand-rp-by-vif-name statement.

On startup it might take up to 1-2 minutes to complete the BSR
election, so in the mean time you won't see any Cand-RP messages.

If the local Cand-RP router is also the elected BSR, then the
Cand-RP messages are not transmitted on the wire, because that state
is propagated internally.

Hope that helps,
Pavlin