Quick question on something I am having trouble finding documentation on.
Does anyone know how a configured RP in a PIM SM implementation become aware
of all multicast groups within a particular network? Are they advertised via
PIM running on each PIM via the multicast routing table?
If I understand what you're asking, then no - RPs don't know about
"groups" in that way.
For a new multicast sender, the PIM DR on the sender vlan sends a PIM
register to the RP. The RP then performs an (s,g) join for the new
source, and and sends a register-stop telling the PIM DR to cease.
Multicast receiver state is propagated by PIM join packets.
In other words, the RP "knows" about a group when someone joins it or
sends to it.
What you need is a msdp session between all RPs that you have configured.
So source PIM enabled routers will register the source multicast group with
That's what I wanted to know thanks.
This link explains the registration process.
Whilst not answering your question specifically, I've always found the series of article written by Peter J. Welcher of the Chesapeake Netscaftsmen a good reference for multicast (fairly easy to read and understand).
http://www.netcraftsmen.net/resources/archived-articles/436-[..] http://www.netcraftsmen.net/resources/archived-articles/376-[..] http://www.netcraftsmen.net/resources/archived-articles/424-[..] http://www.netcraftsmen.net/resources/archived-articles/375-[..]
This sounds like a use case for AutoRP/BSR to me...