Solved: Re: Multicast RPF question

teru-lei · ‎01-19-2003

Hi all,

When config multicast, RPF will be performed when select the route. Can any one explain why RPF is needed? Thank you!

Best Regards

Teru Lei

bbranch · ‎01-20-2003

In it's simplist form it is a method of loop prevention. If you receive a multicast packet on an interface which is also the route to the source then the RPF check has passed and you can send the multicast packet out of all other interface (if required). If you receive a multicast packet on an interface which is not the route to the source then the packet is dropped as the RPF check has failed.

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bbranch · ‎01-20-2003

In it's simplist form it is a method of loop prevention. If you receive a multicast packet on an interface which is also the route to the source then the RPF check has passed and you can send the multicast packet out of all other interface (if required). If you receive a multicast packet on an interface which is not the route to the source then the packet is dropped as the RPF check has failed.