Require Help for Multicasting (MBGP & MSDP Peer)

Unanswered Question
Apr 29th, 2010

Hello All,

We are planning to implement Multicast in our network. This is our network topology.


IPv4 Unicast BGP peer is already configured b/w our Edge Router and TIEN3 Router. Now we want to implement MBGP multicast peer and MSDP peer b/w our Router and Tien3. My question is that can we make MBGP multicast peer and MSDP peer b/w our edge Router and TIEN3 Router or  Should we make peer b/w our RP (CPSP) and TIEN3 .

Can you please guide me and can give some detail answer.

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Overall Rating: 4 (2 ratings)
francisco_1 Thu, 04/29/2010 - 07:41

A good design is to make your local Rendezvous Point the MSDP peer in your site taking care of source registration. In your diagram CPSP is the local RP. CPSP should have MSDP peering with TIEN3. MSDP is the key protocol that makes Anycast RP possible so hence your RP should be your MSDP peer.


wakhan123 Thu, 04/29/2010 - 08:39

Thanks for the reply

Its mean that we should make MSDP peer b/w our Local RP (CPSP) and TIEN3. So what about MBGP peer? Can we make MBGP peer b/w our edge router and TIEN3 , or should we also make MBGP peer b/w our local RP(CPSP) and TIEN3 Router?

You have also mention about Anycast RP, and as per defination Anycast RPs are configured with same loopback address. But as TIEN3 is totally differnet entitiy they must have differnet RP  address and we  have differnet RP address, So how it will be Anycast RP? i think it will be a simple MSDP peer b/w two domains that have differnet RP address.

My knowledge is very limited about multicasting, so please correct me if i am wrong.

wakhan123 Fri, 04/30/2010 - 09:08

Hello All,

Can anyone please tell me that is it necessary to make MBGP peer b/w RPs too, same as MSDP peer b/w RPs. Or we can make MBGP peer b/w our edge routers and then make MSDP peer b/w our RPs.

francisco_1 Fri, 04/30/2010 - 09:17


MBGP (Multiprotocol Border Gateway Protocol) provides the control necessary to decide where multicast packets are allowed to flow. PIM uses the routes associated with multicast routing in oder to build data distribution trees. MBGP provides the RPF path, not the creation of multicast state. Like i said MSDP you should enable on the RP.


francisco_1 Fri, 04/30/2010 - 09:23

You can make your edge router running MBGP, the PIM RP and also MSDP if you like, if the router is capable to handle the responsibilities of RP, MSDP/MBGP

wakhan123 Fri, 04/30/2010 - 09:34


Actually we cannot make our edge router as RP , becoz edge router already have too much load of internet services. We want to make CPSP as our

RP, and as per your advice we will make MSDP peer b/w our RP(CPSP) and TIEN3. Now what about MBGP, should we run it on our RP or on our edge router ?  We already have ipv4 unicast connection b/w our edge router and Tien3. What you think ?

francisco_1 Fri, 04/30/2010 - 09:40

Does your edge router also provides internet services such as internet browsing? does that router have ebgp external peering with your provider?

I thought the edge router only provides connectivity to TIEN3 ? (site-site traffic)


wakhan123 Fri, 04/30/2010 - 09:47

Yes , our edge router have ebgp peer with two differnet service providers for internet services. and it also have ebgp peer with TIEN3. So it have too much load thats why we dont want to use our edge router as RP. we want to use CPSP as our RP.

So can we make direct MBGP/ MSDP peer b/w our our RP (CPSP) and TIEN3.

francisco_1 Fri, 04/30/2010 - 09:56


I am being honest in saying that without a full topology diagram of your network including your platforms, IOS, it's difficult for me to assist you.

Are you in contact with Cisco SE?


wakhan123 Fri, 04/30/2010 - 10:07


My network topology is already attached, only there are two more clouds connected to edge router which we use for internet. Actually we are using Cisco + Huawei routers in our network, and our Edge and CPSP  routers are Huawei Routers.

francisco_1 Fri, 05/07/2010 - 05:35

Ok then Based on your diagram, is  CPSP a core router? how about KU?).



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