set up NAT (network address translation) on local server

[Christopher K. Johnson]

No snat rule in effect!

Was the rule you provided in your original post verbatim?  Because it 
had 'a' instead of the public address.  In fact the rule seemed overly 
specific in other ways too.
Here is what I have for a snat rule where the public (Internet) 
interface is eth1 (substitute your public ip address for a.b.c.d:

-A POSTROUTING -o eth1 -j SNAT --to-source a.b.c.d

Resulting in (again substituted a.b.c.d for the real public address):
Chain POSTROUTING (policy ACCEPT 36819 packets, 4482K bytes)
 pkts bytes target     prot opt in     out     source               
destination        
39065 2513K SNAT       all  --  *      eth1    0.0.0.0/0            
0.0.0.0/0           to:a.b.c.d

If your rule is correct, then you need to activate your iptables file 
rules by:
service iptables restart

Chris
>  pkts bytes target     prot opt in     out     source               destination
>
> Chain POSTROUTING (policy ACCEPT 0 packets, 0 bytes)
>  pkts bytes target     prot opt in     out     source               destination
>   


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