On Wed, May 09, 2018 at 07:38:31AM +0000, Arvin Gan wrote: > Hi all, > > I notice below description in user guide, my understand is source > address mainly used for BGP session for TCP connection ,don't understand > why this source is also used as next_hop_addr calculation.
Hi Generally, BGP speaker have to select reasonable bgp_next_hop address from its IP addresses. BIRD uses by default the source address of BGP session if applicable (like matching AF or ext_next_hop), otherwise it takes preferred IPv4 or IPv6 address of the same iface where is the source address. Or could be explicitly configured by 'next hop address' option. See function bgp_channel_start() for details. -- Elen sila lumenn' omentielvo Ondrej 'Santiago' Zajicek (email: santi...@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."