Multiple routes to the same destination

[Christopher Martin]

> -----Original Message-----
> From: Baldur Gislason [mailto:baldur at foo.is]
> Sent: Friday, 23 June 2006 10:02 PM
> To: Christopher Martin
> Cc: FreeBSD Net Mailing list
> Subject: Re: Multiple routes to the same destination
> 
> Well, round robin is really not what you want with IP packets.
> And how are you going to detect that a route is good without a routing
> protocol?
> 

Actually, round robin is exactly what I want. And I am not saying I don't
use a routing protocol, in fact I do, but I want packets to be able to use
two or more diverse paths of equivalent cost.

It would seem that you are assuming that I want to load balance two internet
connections which are NATed, in which case round robin might have issues
with lost TCP sessions and weird reactions from servers as the apparent
source address changes from packet to packet, but in a routed internal
network the source address will not be changed by the router, thus negating
that issue.

It did seem at some stage someone was going to include it in OpenBSD:
http://undeadly.org/cgi?action=article&sid=20040425183024&mode=expanded

To quote:
"...OSPF also supports multipath equal cost routing".

It's more of a case where we would like to use BSD as a router/packet
filtering firewall for sites with multiple WAN links between each site, of
equal size, and not have one site idle until the other fails over. Round
robin is better than what we have: nothing.