RPF neighbor disappears and appears again

[smailmilak]

Hello people,

I have a weird problem with SSM multicast on Cisco 7609 routers.

R1: 15.1.3-S4, IP 10.100.96.9 on TenG 1/0/0 which is the incoming interface for mcast group 239.192.6.41, behind it are receivers.

R2: 122-33.SRD4, IP 10.100.96.10 on TenG 9/0/0 which is the outgoing interface. Vlan 965 is the incoming interface and there are the sources connected.

The problem is that I lose the RPF neighbor on R1 and the incoming interface becomes "Incoming interface: Null, RPF nbr 0.0.0.0".

On R2 the outgoing interface becomes also "Null". After a few minutes everything comes up and mcast traffic is flowing through the network.

After a few minutes it becomes "Null" again.

I have attached a simple visio drawing and two .txt files with show ip mroute 239.192.6.41 on R1 and R2 when it's working and not working.

Logs are included, too. Debug IP multicast routing debugging is on for 239.192.6.41 is used.

I tried almost every possible debug command.

Please note that other mcast group which are received on other interface on R1 are fine. I have only this problem on R1 TenG 1/0/0 (Incoming)

and R2 TenG 9/0/0 (Outgoing).

I hope that someone can give me a hint how to solve this issue.

P.S. Static mroute solves the problem but this is not a solution!

[smailmilak]

I would like to add that TE is used and the next hop is a TE tunnel

I checked the unicast and multicast routing table and I have observed that when I see a sudden RPF loss

the unicast/multicast routing table, where the next hop is a TE tunnel, the update timer is reset.

Other physical and SVI interfaces are ok, last update is a few weeks ago...

sh ip route multicast 10.120.10.203

Routing Table: multicast

Routing entry for 10.120.10.200/29

  Known via "ospf 8000", distance 110, metric 11, type intra area,

   replicated from topology(default)

  Last update from 10.100.96.251 on Tunnel251, 00:03:48 ago

  Routing Descriptor Blocks:

  * 10.100.96.251 (default), from 10.100.96.251, 00:03:48 ago, via Tunnel251

      Route metric is 11, traffic share count is 1

Any ideas?

[Mohammed Imran Khan]

Hello,

I am not clear about the problem statement. Was this working earlier with the same setup? Is "mpls traffic-eng multicast-intact" configured within the ospf process? If not, can you try to configure this command under "router ospf 8000".

Regards,

Imran

[smailmilak]

Hi,

it was not working since we started to stream from this mcast group and R2.

We are running 15.1.3-S4 which was released two months ago I think. I am not sure if there is a bug

or Cisco has changed something.

And yes, mpls traffic-eng multicast-intact is already in the OSPF config.