How does a PIM-SSM LHR select the multicast source ?
[ Edited ]
3 weeks ago
An IGMP v3 Report message may not be specific about a single source for a requested multicast stream. It may have an INCLUDE source list that contains a list of sources from which any one source would do. Or it may have an EXLUDE source list that contains a list of sources it does NOT want traffic from (any other source would do).
I have two related questions.
If a PIM SSM router receives an IGMPv3 REPORT for group G with an EXCLUDE source list of S1, how does the router decide on a source to send a PIM JOIN to?
If a PIM SSM router receives an IGMPv3 REPORT for group G with an INCLUDE source list of S1, S2 how does it decide which of the two sources to send a PIM JOIN to?
Re: PIM-SSM LHR selection from the IGMPv3 source list.
3 weeks ago
I believe when we have multiple sources in an SSM you will have multiple source based tree formed from the LHR to each source. This is because in SSM we need to have the shortest path source rooted tree and hence for each different source we will have the different source based tree. The source selection will depend on the IGMPv3 feature (INCLUDE/EXLUDE) which determines which source to be included to form the tree and which ones to ignore.