router/nat with only one NIC

[Alma J Wetzker]

Tim Wunder wrote:
> Is it possible to route internal internet traffic through a server that 
> has only one NIC?
> 
> I've only had one PC connected to the internet for quite some time and 
> have it configured to route all internet traffic through squid, 
> squidguard and dansguardian. I want to add a second PC and have its 
> internet traffic routed the same way. The server that runs squid and 
> dansguardian currently has only one NIC. So far, the information I've 
> found on the 'net through googling indicates that I need to have a 
> second NIC in order to do this.
> 
> Is there a way to do it without adding a second NIC?
> 
> I know... NICs are cheap, just buy a second one. It'll just be a pain to 
> have to pull the server out from where it is, then install and configure 
> a NIC. I'm trying to avoid that.

AFAIK, you have a choice:  Add a NIC (about $10 and some fiddling) and run a 
cable to the second machine OR configure all your proxies and firewalls on the 
second computer.  I can't think of a way for you to utilize the protections of 
the server without routing through the server.  If you have a NIC connected to 
the net directly, it is connected to the net directly.

If you are using some sort of firewalling router for network connectivity to 
the world, if no services are open from the world to that system, you should 
be mostly OK.