This article describes the issue of multicast streams not being registered with the RP.
Setup:
Local Network ==> CE (SRX) <==> PE (Router)
Multicast group = 239.28.92.145
To replicate the issue, perform the following procedure:
- Turn on pim traceoptions to see the log messages with flag all.
- In this case study, it was clearly noticed that CE (SRX) was not receiving any PIM join messages from the PE, once the initial setup messages were received for the multicast group (that is, 239.28.92.145 in this example).
- However, the PE device log from (provider) showed that they were sending PIM messages with the 239.28.42.145 join being refreshed at intervals of 1 minute.
- A subsequent test was performed, after this one showed that the PE device continues to send PIM join messages at about 60 seconds intervals, until the receiver on the customer's device (SRX) eventually times out and issues an IGMP leave for the group; which triggers a cascading PIM prune message down into the provider's VPN.
- This is immediately followed by a new IGMP group join, which is followed by the CE device seeing a new PIM join message for the group and the routing state was setup again; only to time out again in 210 seconds, as the CE still reported never seeing a PIM join from the PE after the initial messages.
- The CE logs and the PE logs are contrary to each other. The PE device says that it is consistently sending the PIM joins to refresh the routing state, when the CE device never reports seeing them. One of the devices is reporting incorrectly.
To resolve this issue, match the MTU settings on both the CE and PE.