[LARTC] dual-isp incoming traffic problems

[Daniel Wittenberg]

I have two ISP connections, and am having some issues.  I can connect to
any services on the firewall, like the smtp gateway, but anything on the
internal server only works from one connection.  The lartc guide has a
good example for what to do for services on the box, but leaves it open
for how to handle services on an internal host.  I've tried using
iptables to mark the packets incoming, but that doesn't seem to work.

ip route add default via 1.1.1.254 table T1 dev eth0
ip rule add from 1.1.1.2 table T1   **  Real IP
ip rule add from 1.1.1.3 table T1   **  eth0:0 IP
ip rule add from 1.1.1.4 table T1   **  eth0:1 IP
ip rule add fwmark 1 table T1

and similar for ISP connection #2, with:

ip route flush cache

as the last part.  Any ideas on how to get connections through to the
internal server from both ISP's?



ISP #1  -- 
           \                    
             -- Linux Firewall --  internal server
           /
ISP #2  --

Thanks,
Dan