Multicast RFP Check

[serdarkut]

hi friends,

last night when I was studying multicasting, I realized something interesting maybe.

as you know RFP check is effective on PIM DM, checks unicast route table if multicast packet came from where it should be, according to route table.. what if there is a route-map on upstream router specifyin another path to the same downstream router for multicast traffic, arriving on another interface that downstream router expects from?

am i doing a logic mistake or it should cause a problem? what do u think?

[jarathbu · Accepted solution]

Hello,

The uRFP check is done from the perspective of the router. So in your scenario, if the packets are manipulated to come in on an interface this could cause an issue. The router will do it's own lookup and if the uRPF check fails - the multicast stream will be broken.

I hope this helps.

Regards,

James

[serdarkut]

thank you James, I was just thinking like that but I did not see an issue about this on any documents while I am studying for ccie lab. It should be a good question topic on the lab I think :)

thanks again

regards

Serdar