Re: RPF-Meanin

Hi Ismail,

On Fri, Jun 26, 2009 at 1:20 PM, ismail mohamed<mmismail1979_at_gmail.com> wrote:
> Hi,
> What is the meaning of RPF in Multicast ?

You should beef up on the RPF concepts in general, but here's a couple
of points on the RPF check:

- If a packet *destined* for a *multicast group address* arrives at an
interface, and that interface *is not* the interface the router would
use to reach the *source address* of the packet (by consulting the
unicast routing table), the packet _fails_ the RPF check.

- If a packet *destined* for a *multicast group address* arrives at an
interface, and that interface *is* the interface the router would use
to reach the *source address* of the packet (by consulting the unicast
routing table), the packet _passes_ the RPF check.

It's as simple as that.

I recommend reading 'Developing IP Multicast Networks' and the
multicast chapter in 'Routing TCP/IP vol. 2'.

cheers,
Dale

Blogs and organic groups at http://www.ccie.net
Received on Fri Jun 26 2009 - 19:08:16 ART