[Xorp-users] Possible bug in Point-to-Point code in XORP

[Pavlin Radoslavov]

> Using "route add -host 158.234.90.23 off0"
> Xorp> show pim mrib
> DestPrefix         NextHopRouter   VifName VifIndex MetricPref Metric
> 158.234.90.23/32   0.0.0.0         off0    1               254  65535
> 192.168.1.0/24     192.168.1.6     eth0    0                 0      0
> 192.168.10.0/24    192.168.10.2    off0    1                 0      0
> 192.168.10.2/32    192.168.10.2    off0    1                 0      0
> One gets the error message:
> [ 2005/05/01 12:30:09 WARNING xorp_pimsm4 PIM ] JoinDesired(*,G) =
> true: upstream neighbor for RP 158.234.90.23 for group 233.64.38.50:
> not found
> 
> Using "route add -host 158.234.90.23 gw 192.168.10.1"
> Xorp> show pim mrib
> DestPrefix         NextHopRouter   VifName VifIndex MetricPref Metric
> 158.234.90.23/32   192.168.10.1  off0    1               254  65535
> 192.168.1.0/24     192.168.1.6     eth0    0                 0      0
> 192.168.10.0/24    192.168.10.2    off0    1                 0      0
> 192.168.10.2/32    192.168.10.2    off0    1                 0      0
> 
> The WARNING disappears, and the upstream neighbor is found.
> 
> So, I conclude that XORP has a problem with Point-to-Point links where
> one uses the interface name in the route entry instead of the IP
> address.
> 
> Luckily I am using numbered Point-to-Point links, but XORP would fail
> to function if un-numbered point-to-point links were being used.

Yes, currently the PIM-SM implementation doesn't support unnumbered
point-to-point links.
Indeed, even on numbered p2p links the next-hop information should
be an IP address (except for the subnet of the p2p link itself).
This should be fixed in the future, but for the time being you need
to use a solution as the one you describe above.

Now the ERRATA file contains an entry for this issue.

Thanks for the observation,
Pavlin