RE: UDP stream load balancing across multiple uplinks

["Barry A Rich" <barich@trisectrix.com>]

> -----Original Message-----
> From: netfilter-owner@vger.kernel.org
[mailto:netfilter-owner@vger.kernel.org]
> On Behalf Of ??????????? ??????
> Sent: Monday, August 04, 2008 3:26 AM
> To: barich@trisectrix.com
> Cc: 'Mail List - Netfilter'
> Subject: RE: UDP stream load balancing across multiple uplinks
> 
> В Пнд, 28/07/2008 в 09:33 -0400, Barry A Rich пишет:
> > > -----Original Message-----
> > > From: netfilter-owner@vger.kernel.org
> > > [mailto:netfilter-owner@vger.kernel.org]
> > > On Behalf Of Grant Taylor
> > > Sent: Friday, July 25, 2008 11:10 AM
> > >
> > > Given that the source IP of your packets can change mid stream, you
> > > could use the "nth" match extension.  Using "nth" you would match
> > > packets to decide how to mark them and then use the mark to determine
> > > what routing table to use which would ultimately decide which outbound
> > > path to use.
> >
> > The following setup does load balancing across the uplinks. However, the
> > source address in the outgoing packets is not being SNAT'ed. Any
> > suggestions?
> 
> Only first packet of udp "connection" is reaching the rule in the nat
> table and does the job, since nat occurs for all packets in this
> connection rest of rules would not match.

I understand better. I removed the following rule:

#iptables -t raw -A PREROUTING -i eth0 -p udp --sport $SPORT -j NOTRACK

The connection is tracked and the outgoing UDP packets are SNAT-ed. However,
the source address for all UDP packets is the IP address of the uplink
assigned to the connection (regardless of the uplink they actually are
sent).

Is there a way to SNAT without connection tracking?