NAT iptables routing issue

[Caveman <biocorporation-1@optusnet.com.au>]

Hi all,

I have a slight problem I am not sure how to get around.
Firstly let me draw you a picture. I have computer 'A' which is directly 
connected to the internet and is the ONLY computer to have a internet IP. 
It routes (via nat ) traffic from clients on the lan to the internet etc.

Now on box 'B' I have a webserver running and I have forwarded (using 
prerouting) port 80 to box 'B''s LOCAL IP. This works fine for people outside 
my network (IE, the internet) but I cant access the webserve by using the 
internet IP from the lan, its never been a big issue, but i have finally 
decided that I need to work out how to fix this.

Any ideas ? The below code is my NAT and prerouting stuff i have setup. I know 
that the postrouting rule i have now is whats causing the issue, but I am 
unsure as to how I should get around this.


Thanks.

Caveman

-----------------------------------
#NOTE eth0 is connected to the internet, eth1 is lan.
# flush any old rules
$IPTABLES -F -t nat
# turn on POSTROUTING
$IPTABLES -A POSTROUTING -t nat -o eth0 -j MASQUERADE
#forward port 80 from INTERNET IP connections to 192.168.0.2 port 80
$IPTABLES -t nat -A PREROUTING -p tcp -i eth0 --dport 80 -j DNAT --to 
10.1.1.2:80
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