ā06-20-2010 05:21 PM - edited ā03-04-2019 08:50 AM
Hi,
When we enable a network in BGP process
network a.b.c.d mask 255.255.255.0 nlri unicast multicast
For normal unicast : it will advertize a subnet a.b.c.d / 24 to it's peer but what's the deal with multicast?
It seems me like "When there is a user who wants to receive a stream of any particular multicast IP address ( Mult_Addr_1) who is connected to the LAN which this router is advertizing in our case a.b.c.d/24 - BGP will inform it's peers that it needs a stream of Mult_Addr_1. A kind or way informing that it has a route to Mult_Addr_1."
When we peer with BGP only for multicast as follows:
neighbor p.q.r.s remote-as xyz nlri multicast
What actually takes place how does it helps or enables Multicast routing or forwarding for multicast packets? ( or does it helps PIM )
Please share the experience.
Thanks in advance
Subodh
ā06-20-2010 09:26 PM
Hi,
This link provides good explanation of MBGP
http://www.cisco.com/en/US/docs/ios/12_0t/12_0t7/feature/guide/mbgp.html#wp1020650
Hope this helps
Hitesh Vinzoda
Pls rate useful posts.
ā06-21-2010 08:06 AM
Hello Subodh,
we use BGP in inter AS multicast to advertise NLRI of possible multicast sources not multicast groups.
This is done in order to pass the RPF check on border router:
the border router will accept incoming multicast traffic if the source can pass the RPF check.
One effect of the capability to differentiate NLRI per sub address family is that you can dedicate a link to multicast traffic and you can keep multicast traffic separated from unicast traffic.
MSDP can be used to advertise the existence of sources but it is not enough to pass RPF check
So this is an help in passing RPF check
Hope to help
Giuseppe
Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community: