RE: UDP stream load balancing across multiple uplinks

["Покотиленко Костик" <casper@meteor.dp.ua>]

В Пнд, 04/08/2008 в 09:57 -0400, Barry A Rich пишет:
> > -----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?

Sure:

http://linux-ip.net/html/nat-stateless.html

-- 
Покотиленко Костик <casper@meteor.dp.ua>