Hi,
I test nexus 5600 [NX-OS 7.3(1)N1(1)] as pim-sm multicast rp with using pim register-policy to control allowed multicast sources and groups.
For using the "ip pim register-policy" command I configured a route-map like
route-map rm_registertest permit 10
match ip multicast source 10.0.0.1/32 group 239.192.100.100/32
route-map rm_registertest permit 20
match ip multicast source 10.123.123.1/32 group 239.192.100.100/32
...
When sending a multicast stream not allowed in the route-map this stream will be registered by the first hop router (Catalyst 6K Switch) endlessly. That means "show ip mroute" will show registering state endlessly,
firsthop-router#sh ip mroute
...
(10.123.123.1, 239.192.200.200), 00:13:44/00:01:10, flags: PFT
Incoming interface: Vlan2222, RPF nbr 0.0.0.0, Registering
Outgoing interface list: Null
and "show ip pim policy statistics register-policy" on rp (Nexus 5600) will increase comparison counts of every route-map entry endlessly.
mcast-rp# sh ip pim policy statistics register-policy
route-map rm_registertest permit 10
match ip multicast source 10.0.0.1/32 group 239.192.100.100/32 C: 571192 M: 0
route-map rm_registertest permit 20
match ip multicast source 10.123.123.1/32 group 239.192.100.100/32 C: 571192 M: 0
...
Total accept count for policy: 18
Total reject count for policy: 571192
So it seems that the rp does not send a register-stop to the fhr, which results in the fhr endlessly registering (incl. encapsulating) the stream and the rp endlessly decapsulating/checking/dropping this stream. No good when it's a 3Gb/s video stream; yes we already use register-rate limit on the fhr to prevent this but I think it would be better if fhr would drop the stream instead of endlessly registering.
When using a catalyst 6K as rp (= IOS and "ip pim accept-register <acl>" configuration) in the same scenario it seems that the rp sends a register-stop to the fhr because there is no registering state in the mroute table.
firsthop-router# sh ip mroute
...
(10.123.123.1, 239.192.200.200), 00:00:12/00:02:47, flags: PFT
Incoming interface: Vlan2222, RPF nbr 0.0.0.0
Outgoing interface list: Null
Does anybody know if nexus behaviour can be changed to send register-stops? Or is there any other possibility to solve this issue?
Best regards
Thorsten
