Iptables forward

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Problem:
Computer A (Internal Win2k)-------: IP: 10.0.0.1
Computer B (Linux Box)------------: IP: 136.201.105.2
Computer C (General Internet pc)--: IP: 136.206.111.3

Computer B has 1 network card. It is on the same LAN as Computer A and has external Internet Access.
Computer B can access both Computer A and Computer C.



There is a Webserver on Computer A -> 10.0.0.1:80
Computer C (general internet) cannot access the above Webserver on Computer A.

We want to use Computer B to forward all traffic from Computer C to Computer A.


iptables firewall can be used to forward such connections.

The Setup:

Going from Scratch:

iptables -F
# Flush rules from iptables

iptables -t nat -F # Flush rules from nat table in iptables
iptables -t nat -A PREROUTING -p tcp -d 136.201.105.2 --dport 80 -j DNAT --to 10.0.0.1:80 iptables -t nat -A POSTROUTING -d 10.0.0.1 -j MASQUERADE

If Computer C types http://136.201.105.2 into their Internet, they will see the Webserver on Computer A (10.0.0.1).

This Works. Will get around to perhaps explaining it later.

Look at the complete Iptables_Firewall


Further Information at:
http://documents.made-it.com/Debian_Internet_Server/Debian_Internet_Server-13.html
http://lists.debian.org/debian-user/2002/08/msg00112.html

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