LARTC - Aug 2006 - route mail through different gateway

Hi All,

I''ve got server with one LAN card eth0 ip=10.0.0.5

default access t ointernety done through ADSL router gw 10.0.0.1
we got second internet access through another ADSL router gw 10.0.0.2

I want to send all e-mail out through gw 10.0.0.2
How it can be done?
I''ve tried to mark packets:
iptables -t mangle -A OUTPUT -p tcp --dport 25 -j MARK --set-mark 0x1
and
ip ru add fwmark 0x1 table mail.out
ip ro add default via 10.0.0.2 lookup mail.out

But it is dosen''t work
Any help?

-- 
--
Michael


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Silly mistake I always make is too forget to put in NAT on GW.
But what you have done should work. Have you confirmed that this works

on 10.0.0.5
ip route del default
ip route add default via 10.0.0.2
ip route flush cache

If that works maybe try
# Dont know which one of these I think your right it should be output
iptables -t mangle -A PREROUTING -p tcp --dport 25 -j MARK --set-mark
0x1 
iptables -t mangle -A OUTPUT -p tcp --dport 25 -j MARK --set-mark 0x1 
ip rule add from 10.0.0.0/8 fwmark 1 lookup 200
ip route add default via 10.0.0.2 table 200

# The I would try tcpdump -vv -ni eth? and look at the MACs
# or  and check the mark
iptables -I POSTROUTING -p tcp --dport 25 -j LOG

On Fri, 2006-08-04 at 14:36 +1200, Michael wrote:
> Hi All,
> 
> I''ve got server with one LAN card eth0 ip=10.0.0.5
> 
> default access t ointernety done through ADSL router gw 10.0.0.1
> we got second internet access through another ADSL router gw 10.0.0.2
> 
> I want to send all e-mail out through gw 10.0.0.2
> How it can be done?
> I''ve tried to mark packets:
> iptables -t mangle -A OUTPUT -p tcp --dport 25 -j MARK --set-mark 0x1 
> and 
> ip ru add fwmark 0x1 table mail.out
> ip ro add default via 10.0.0.2 lookup mail.out
> 
> But it is dosen''t work
> Any help?
> 
> -- 
> --
> Michael 
> _______________________________________________
> LARTC mailing list
> LARTC@mailman.ds9a.nlhttp://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc

On 04-08-2006 04:36, Michael wrote:
> Hi All,
> 
> I''ve got server with one LAN card eth0 ip=10.0.0.5
<http://10.0.0.5>
> 
> default access t ointernety done through ADSL router gw 10.0.0.1 
> <http://10.0.0.1>
> we got second internet access through another ADSL router gw 10.0.0.2 
> <http://10.0.0.2>
> 
> I want to send all e-mail out through gw 10.0.0.2 <http://10.0.0.2>
> How it can be done?
> I''ve tried to mark packets:
> iptables -t mangle -A OUTPUT -p tcp --dport 25 -j MARK --set-mark 0x1
> and
> ip ru add fwmark 0x1 table mail.out
> ip ro add default via 10.0.0.2 <http://10.0.0.2> lookup mail.out
You mean:

ip ro add default via 10.0.0.2 table mail.out

Try this also:

echo 0 > /proc/sys/net/ipv4/conf/all/rp_filter

Jarek P.

PS: I hope you have this mail.out properly added (or replace this 
with a number e.g.: 100) and fwmark enabled in kernel config.