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General question about DVMRP protocol

According to the multicasting idea over the entire Internet, I have been read that  DVMRP protocol is the multicasting protocol used in the multicast backbone area. 

What are the reasons that stand behind preferring DVMRP, over other multicasting protocols in the backbone area? 

 

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Re: General question about DVMRP protocol

Hello @Abdel-Nasser ,

DVMRP was the multicast routing protocol of choice in M-bone an experimental network between universities and it has just an historical value.

M-bone worked heavily on tunneling over standard IPv4 unicast internet.

Modern vendor implementations of IP multicast use PIM sparse mode  (ASM any source Sparse mode requires an RP rendez-vous point and SSM source specific multicast), even PIM dense mode has limited usage now  (for example it is not supported in IPv6).

Cisco routers configured for ip4 multicast routing are able to understand DVMRP updates but they do not send out DVMRP updates.

DVMRP is a dense mode IP routing protocol (it thinks all subnets need to receive the traffic flood and prune) and it is derived by RIP. It is a distance vector protocol.

In DVMRP the infinite metric should be 63.

Being a distance vector protocol it cannot compete with modern protocols in terms of convergence time.

This is likely the reason why it is not used anymore in production networks.

 

Edit:

on the contrary PIM = Protocol Indipendent multicast can use whatever unicast routing protocol is in use OSPF, EIGRP and so on to perform the RPF check : that is to find the nearest interface to the source of the multicast stream. Only traffic matching the RPF check is propagated to other multicast enabled interfaces.

By doing so PIM is focused only on RPF check and does not try to build its own unicast routing protocol. This was the key for its success.

PIM was introduced by Cisco and later it becomes a standard described in several  IETF RFCs.

 

Hope to help

Giuseppe