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New Member

Resilient Multicast Sources

Hi,Im looking at adding a Resilient IPTV source to our network, which will use the same Source/Group entries as the primary Source, in the anticipation of users failing over to this in event of primary source failure.

Obviously under normal circumstances, using PIM-SM, a user would receive both streams, resulting in a corrupt output.

SSM appears to be the answer, however, having read up on it, it seems as though Receivers filter-out the source they wish to receive, based upon its MAC address, and ignore the other source (I assume the originator MAC is transmitted in an upper OSI layer). Is there a mechanism to failover to the other MAC at the receiving end, in event of failure of the primary source...?

And is this the best way to acheive my objective?

Any advise gratefully accepted, Thanks...

New Member

Re: Resilient Multicast Sources


I was searching the same information, if anyone have some clue, that should interest me as well.



Cisco Employee

Re: Resilient Multicast Sources


With PIM-SM, you will not receive both streams as the RP build only one source tree up to its closest source. I agree with you if the sources IP address are different.

When the router connected to the receiver switch to the SPT, it may build a tree up to the other source if this one is closer.

With PIM-SSM, the router connected to the receiver will build a SPT up to the router connected to its closest source.

Depending on your topology, IGP configuration,.. the root of all the SPT's may not be the same router. You also have a dynamic convergence based on your IGP if you loose a source.

If you don't want to load-share between the source, you will have to play with the subnet mask of the two source LAN so the primary one is shorter (prefer by the IGP). Of course the source @ must reside on both subnets.