Problems configuring multihop BGP setup

[Ondrej Zajicek]

On Fri, Jul 23, 2021 at 05:29:54PM +0200, Rainer Kulow wrote:
> Thank you for the detailed explanation.
> I understand, since "multihop" was specified, it tried to resolve the
> gateway recursively - which didn't work because the matching routes were
> missing in the routing table. 
> 
> When I deleted "multihop", the next hop was taken directly from
> "bgp_next_hop", which does not need lookup from the route table. 
> This was at least possible for the next AS, for the further ones logically
> not anymore.  

It should work even for the further ones, becase when EBGP router forwards
a route to a different, it changes the bgp_next_hop to itself.

So if you have AS1 - AS2 - AS3, then AS2 forwards route from AS1 to AS3,
changes the bgp_next_hop to itself, so AS3 sees route to AS1 with
bgp_next_hop to a router from AS2.

-- 
Elen sila lumenn' omentielvo

Ondrej 'Santiago' Zajicek (email: santiago at crfreenet.org)
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"To err is human -- to blame it on a computer is even more so."