[lug] help with iptables

[Carl Wagner]

Hi,

I have an application where I need to do SourceNAT, but don't want to 
change the source IP for traffic originating on the local box.

This is the script I am using to try to allow the servers out to the 
Internet:

======
#!/bin/bash
# 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 Source-NAT
iptables --table nat --append POSTROUTING --out-interface eth0 -j SNAT 
--to {a public IP behind a firewall}
iptables --append FORWARD --in-interface eth1 -j ACCEPT

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

How would I exclude the local boxes IP's/localhost from the SourceNAT?

Thanks,
Carl