On Tue, Jan 07, 2020 at 12:05:21PM +0000, Neil Jerram wrote:
On Tue, 7 Jan 2020, 00:39 Ondrej Zajicek, <santiago@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@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."