BGP RR next-hop-self on eBGP NLRI

[Jacob Zartmann]

Hi,

I'm designing a DMVPN cloud with RR and ran into what I think is a weird behaviour with BGP and next-hop.

Say my RR receives a prefix of 1.1.1.0/24 from the Nonclient that I have a eBGP neighborship with... This prefix is then propagated to my Client. According to my knowledge of BGP and how next-hop is set for iBGP/eBGP peers, the next-hop should be the one of my Nonclient when I advertise it to my internal peers. Correct?

Please see attached drawing for reference.

Thank you.

BR,

/JZ

[r.malviya]

Jacob ,

Non-client is just treated as ebgp connection in RR .

& when any ibgp / RR Client learned any prefix from ebgp / RR its next hop should be the same .

but on RR or advertising router if you put nexthop self command it will adversing that prefix with RR or border router ip which is reachable from your network

otherwise without this when we do revirse look up its not able to trace or ping to far end device / IP its unreachable

Regards

Ritesh

[Jacob Zartmann]

Hello Ritesh,

Thanks for your reply.

I don't do neighbor client next-hop-self on the RR which is why I think it is odd behaviour.

Running IOS 15 by the way.

BR,

/JZ

[r.malviya]

Hi Jacob ,

Let us know if you have othe query  & if u feel u r issue resolve pls rate this post .

Regards

Ritesh