I have a single multicast source (Server A) sending to destinations 18.104.22.168 and 22.214.171.124, the source being directly connected to Switch A on VLAN 100.
Switch A is sending dozens of multicasts from multiple VLANs to Router B.
Router B is connected to Switch A on VLAN 200. There is also a client connected to VLAN 200 on switch A directly.
For the two multicasts 226 and 227, multiple days were spent diagnosing the issue until 226 just started to "work". No changes had been made.
227 continues to not work, despite being requested from the same device that requested 226 and eventually received it.
Full mroute entries for 226 (the working one):
(*, 126.96.36.199), 1d21h/00:03:22, RP 10.0.0.1, flags: S Incoming interface: Null, RPF nbr 0.0.0.0 Outgoing interface list: Vlan200, Forward/Sparse, 00:00:07/00:03:22 (188.8.131.52, 184.108.40.206), 1d21h/00:01:50, flags: T Incoming interface: Vlan100, RPF nbr 0.0.0.0 Outgoing interface list: Vlan200, Forward/Sparse, 00:00:07/00:03:22
full mroute entries for 227 (Not working, coming from same source and requested by same client)
(*, 220.127.116.11), 7w0d/00:02:59, RP 10.0.0.1, flags: SJC Incoming interface: Null, RPF nbr 0.0.0.0 Outgoing interface list: Vlan200, Forward/Sparse, 00:00:30/00:02:59 Vlan100, Forward/Sparse, 00:33:28/00:02:20
Troubleshooting steps taken:
- Verified that the source is definitely sending multicast out correct interface
- Verified that I could join from a client directly connected to VLAN 100
- Added a port to Switch A in VLAN 200, and I could not join from a client connected to that port
- A new multicast coming from server A on VLAN 101 works fine.
Server A (VLAN 100) -> 18.104.22.168 -> (VLAN 200) client B: Didn't work for two days, then started to work with no changes made
Server A (VLAN 100) -> 22.214.171.124 -> (VLAN 200) client B: Started testing after 226 started to work inexplicably. This one still doesn't work
Server A (VLAN 101) -> 126.96.36.199 -> (VLAN 200) client B: Worked right away
The configuration for each SVI (100, 101, 200) is identical regarding PIM configuration:
ip pim dr-priority 100 ip pim sparse-mode
What could cause this behavior?