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New Member

BGP and MPLS peerings

Hey All,

I was wondering if someone could help remind me whether or not BGP and / or MPLS LDP peerings have to occur using a / 32 address.  If so, why?

Thanks in advance!


Everyone's tags (3)

BGP and MPLS peerings

do you mean IP addresses on loopback interfaces? It's not really necessary, you can use just a normal "link-net" address, but BGP and MPLS needs an uniqe router-id, and a loopback IP is normaly used for this.

New Member

Re: BGP and MPLS peerings

And of course any /32 would require some form of routing (static or other for reachability) as opposed to say using a /30 address on a pt-pt Ethernet link for peering which would be picked up by the local network..

Sent from Cisco Technical Support iPad App

Re: BGP and MPLS peerings

hi David,

you right you need a host route /32 for MP-BGP with MPLS

You need to use a /32 loopback as the router id for LDP. Without this the PHP is happening one hop too early. This causes to recieve an untagged frame instead of a MPLS frame

however for normal eBGP or iBGP you can use any interface with any subnet as long as it is reachable via IGP or directly connected

hope this help

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