ECMP/multipath support

[Joakim Tjernlund]

owner-bird-users at atrey.karlin.mff.cuni.cz wrote on 2010/12/17 12:10:55:

> From: Joakim Tjernlund <joakim.tjernlund at transmode.se>
> To:
> Cc: Andrew Lemin <andrew.lemin at monitorsoft.com>, Vincent Bernat <bernat at luffy.cx>, bird-users at trubka.network.cz, Ondrej Zajicek <santiago at crfreenet.org>
> Date: 2010/12/17 12:11
> Subject: Re: ECMP/multipath support
> Sent by: owner-bird-users at atrey.karlin.mff.cuni.cz
>
> >
> > Ondrej Zajicek <santiago at crfreenet.org> wrote on 2010/12/17 00:50:41:
> > >
> > > On Thu, Dec 16, 2010 at 08:41:24PM +0100, Joakim Tjernlund wrote:
> > > > This will find any ptp link that matches and several of them will match.
> > >
> > > Not really. For unnumbered ptp links (where sharing of IP addresses
> > > between several interfaces is common), the match is based on interface
> > > ID, which is unique. For numbered ptp links, the match is based on
> > > IP address, but in that case sharing IP addresses (and therefore
> > > network prefixes) is pathological and would cause other problems.
> >
> > I don't remember all the details anymore but sharing IP address for numbered
> > ptp I/Fs is not pathological. It should just work. Also any combination of
> > numbered vs. unnumbered, IP address or no IP address(even pppd supports no IP address
> > on ptp links).
> > If you do it my way you can combine ptp links any way you want and it will scale better too.
> >
>
> Something like this. It is not tested at all and and very simple.

Here is version 2, even simpler :)