Follow up question on "next hop self"

[Ondrej Zajicek]

On Tue, Jan 07, 2020 at 12:05:21PM +0000, Neil Jerram wrote:
> On Tue, 7 Jan 2020, 00:39 Ondrej Zajicek, <santiago at crfreenet.org> wrote:
> > > > Well, you can run just IBGP, if you use direct + 'next hop self'
> > options,
> > > > which should be OK in your simple topology.
> > > >
> > >
> > > According to my understanding of the BIRD code, 'next hop self' is only
> > > relevant when exporting a locally originated route to a BGP peer.  So,
> > > assuming the original question was about what happens on R1 and R2, I
> > would
> > > not expect it to be relevant at all.   Is that right?
> >
> > Option 'next hop self' is relevant in both exporting locally originated
> > route to a BGP (i.e. a route without existing bgp_next_hop attribute) and
> > exporting route from BGP to another BGP (i.e. a route with existing
> > bgp_next_hop attribute).
> >
> 
> Thanks, yes, I should have mentioned the second case too.
> 
> But both cases are on export, so I think my point still stands that 'next
> hop self' is not relevant to the question that began this thread. (Unless I
> misunderstood that question.)

Yes, 'next hop self' is relevant just for export, that is why i suggested
direct + 'next hop self' - 'next hop self' on export side ensures that
direct (or rather 'gateway direct') on import side has reachable next hop
address.


-- 
Elen sila lumenn' omentielvo

Ondrej 'Santiago' Zajicek (email: santiago at crfreenet.org)
OpenPGP encrypted e-mails preferred (KeyID 0x11DEADC3, wwwkeys.pgp.net)
"To err is human -- to blame it on a computer is even more so."