What is PIM Designated Forwarder ?

Dear All,
Can any one please clearly mention a simple way to explain the basic
difference between the PIM DF (Designated Forwarder) and PIM DR (Designated
Router).
I know PIM DR, usually is a router connected next to the multicast source in a
network which registers with the RP by sending a UNICAST register message
inside multicast packet and informs the RP about a multicast source in a
netwrok.

The pim DF is related to PIM Bi-Directional multicast flavor, but how it
differs from the DR, since its also elected onto a segment and then is
responsible for avoiding loops in multicast by creating a loop free Source
path tree.

I need real help in understanding a DF concept and Bi-Directional at the same
time?
I could not find the better link to make a better concept if one can advise a
better link , that will be highly appreciated!

thanks

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Received on Wed Nov 03 2010 - 09:36:29 ART