What does your nat table look like:
iptables -t nat -n -L

Chain PREROUTING (policy ACCEPT)
target prot opt source destination
DNAT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:80 to:192.168.0.2
DNAT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:22 to:192.168.0.2
DNAT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpts:2300:2400 to:192.168.0.2
DNAT udp -- 0.0.0.0/0 0.0.0.0/0 udp dpts:2300:2400 to:192.168.0.2

Chain POSTROUTING (policy ACCEPT)
target prot opt source destination
MASQUERADE all -- 0.0.0.0/0 0.0.0.0/0

Chain OUTPUT (policy ACCEPT)
target prot opt source destination

FYI i've checked the actual connectivity. The windows system can talk to eth1, but not to eth0 or the world. The linux system via eth1 can talk to the windows system, but the world can't talk to the windows system.

Ah - sorry I assumed that your server had access to the net through linux already.
What happens when you run:
cat /proc/sys/net/ipv4/ip_forward

If it returns 0 then:
echo 1 > /proc/sys/net/ipv4/ip_forward

and try again.

Oh - and when you say windows has no access to the net - I take it that was after making sure that the default gateway was set to the ip of the linux box - yes?

IP_Forward is already set to 1. I also added a line to sysctl.conf reading net.ipv4.ip_forward = 1

Yes, the gateway on the windows system is set to 192.168.0.1

Ok - something is odd here - what do the routing tables look like?

route returns:

Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.0.0 * 255.255.255.0 U 0 0 0 eth1
10.255.255.0 * 255.255.255.0 U 0 0 0 eth0
169.254.0.0 * 255.255.0.0 U 0 0 0 eth1
127.0.0.0 * 255.0.0.0 U 0 0 0 lo
default 10.255.255.1 0.0.0.0 UG 0 0 0 eth0

/etc/iproute2/rt_tables contains:

#
# reserved values
#
#255 local
#254 main
#253 default
#0 unspec

#
# local
#
#1 inr.ruhep



ip route returns:

192.168.0.0/24 dev eth1 scope link
10.255.255.0/24 dev eth0 proto kernel scope link src 10.255.255.5
169.254.0.0/16 dev eth1 scope link
127.0.0.0/8 dev lo scope link
default via 10.255.255.1 dev eth0

when i do serivice --status-all one of the lines returned is:

ipchains: Incompatible with this kernel

I think i'm going to do a reinstall...

ipchains? why are you using ipchains?

I'm not using IP chains. That was just erroneous information.

Ah sorry I see it was a query to ipchains. That is just because it is installed. No need to worry.

I just can't figure this one out though. Your routing is fine. Forwarding is enabled and an iptables rule is in place and yet you still can't masq out or forward in.

How about trying to get this working one bit at a time.
With the windows server's gateway set to the linux boxes ip what happens if you:
ping www.linuxquestions.org
ping 64.179.4.146

I can't ping linuxquestions.org from the windows box. I'll have my system setup later tonight on a T1 with a static+public IP. Maybe life will get simpler... and I'll reinstall more carefully.

Does that mean you can ping the ip address?

I can ping the IP address from the linux machine. However, I cannot ping the IP from the windows machine. The reinstall's going to have to wait till tommorow. I forgot my CD-Rs []

Just an additional question...

How can oen test if IPTABLES rules actually work properly, besides noticing that a particualr service doesn't work.

Thanks