[Xorp-users] two BSRs

[Mikael Johansson]

On Fri, Apr 4, 2008 at 7:24 PM, Pavlin Radoslavov
<pavlin at icsi.berkeley.edu> wrote:
>
> Pavlin Radoslavov <pavlin at ICSI.Berkeley.EDU> wrote:
>
>  > Mikael Johansson <johansson500 at gmail.com> wrote:
>  >
>  > > I am trying to configure two BSRs so that one router is BSR for some
>  > > multicast groups and another router is BSR for different multicast
>  > > groups.
>  > >
>  > > Routers are connected like this:
>  > >
>  > > A --- B --- C
>  > >
>  > > Both Router B and Router C are defined as BSR candidates, Router B for
>  > > 225.13.0.0/24 (eth1, 10.0.0.1) and Router C for 225.12.0.0/24 (eth1,
>  > > 10.0.0.2).
>  > >
>  > > I would expect to see both 10.0.0.1 and 10.0.0.2 as BSRs on Router A,
>  > > but command "show pim bootstrap" on Router A shows only one BSR:
>  >
>  > You need to check the following:
>  >
>  > * Are the Bootstrap messages from C forwarded by B on the
>  >   A-B subnet.
>  >   For that purpose you need to use a tool like tcpdump or
>  >   wireshark that understands the Bootstrap messages format so you
>  >   could match the content. Note that the Bootstrap messages are
>  >   processed hop-by-hop such that only the payload of the message is
>  >   preserved, but the IP header is replaced (i.e., the src IP address
>  >   won't match the BSR IP address).
>  >
>  > * Check that the (unicast) reverse-path forwarding information in A
>  >   points to B as the next-hop toward C.
>  >
>  > * Check for any suspicious warning or error messages in the XORP log
>  >   output.
>
>  Ignore the above.
>  On second thought, I think the problem is that inside your
>  "scope-zone {}" nodes you must set "is-scope-zone: true",
>  because it is false by default.
>
>  For reason for that is according to the PIM BSR spec there is one
>  BSR state machine per scope zone.
>  If a configured zone's "is-scope-zone" flag is false, then it
>  automatically belongs to the global 224.0.0.0/4 non-scoped zone.
>  I.e., in your configuration both configured entries for
>  225.13.0.0/24 and 225.12.0.0/24 will be controlled by the same state
>  machine.
>
>  Setting the "is-scope-zone" flag to true for at least one of them
>  will put them on separate state machines, but a good practice would
>  be to enable the "is-scope-zone" flag for both of them.
>
>  Please let me know whether this fixes the problem.
>
>  Pavlin

I set "is-scope-zone" flag to true, and now I see both BSRs on Router A.

Thanks,
Mikael