Hi all.
Ive used this (10.4.*Multiple Connections to the Internet) very usefull guide on how to route traffic to multiple internet connections based on traffic type (http isp1 ftp isp2). It works a treat. However, it works as long as the machine that is accessing the internet resource is not the router pc itself. Heres what Ive got so far:

Fedora Core 6 setup with IP forwarding and iptables as the firewall 3 network cards - one network card going to isp1 (eth1) another going to isp2 (eth2) and another to connected to the LAN (eth0)
Ive set it up as a router as per Using Linux iptables or ipchains to set up an internet gateway / firewall / routerfor home or office.
Which basically says:

# Delete and flush. Default table is "filter". Others like "nat" must be explicitly stated.
iptables --flush - Flush all the rules in filter and nat tables
iptables --table nat --flush
iptables --delete-chain - Delete all chains that are not in default filter and nat table
iptables --table nat --delete-chain

# Set up IP FORWARDing and Masquerading
iptables --table nat --append POSTROUTING --out-interface eth1 -j MASQUERADE
iptables --append FORWARD --in-interface eth0 -j ACCEPT

echo 1 > /proc/sys/net/ipv4/ip_forward - Enables packet forwarding by kernel

That all works great. Next Ive got the stuff needed for the conditional routing:
iptables -t mangle -A PREROUTING -p tcp --dport 81 -s 192.168.99.0/24 -j MARK --set-mark 4
iptables -t nat -A POSTROUTING -o eth1 -j SNAT --to-source xxx.xxx.xxx.xxx <-public ip address of isp1
iptables -t nat -A POSTROUTING -o eth2 -j SNAT --to-source xxx.xxx.xxx.xxx <-public ip address of isp2

there are some ip rules that get added that act upon the --set-mark:
ip rule add fwmark 4 table 4

I use port 81 as test, by setting up a remote web server that listens on port 81 and tells me (via php) what my ip address is.

Like I said, works a treat, as long the pc I use to browse (or whatever) is not the router pc itself, but id like it to work from the router pc as well as remote stations. Any suggestions greatly appreciated.

PresidentScroob.