Sharing internet but not network

[DarrylSEI]

I have one workstation that i would like to share the internet but not have access to my network neighborhood at all.

I have attached a diagram of our network. The black lines show how our network is currently connected. We have someone in our office that does not work with us (Workstation X). We want him to be able to use the internet. but not be able to see our network neighborhood. My original idea, which you can see in red, was to output our Router into a Hub and from the Hub hook up both our Firewall and Workstation X. Unfortunately, Workstation X was still able to browse our network. (I can't understand how Workstation X is able to see our network even though it is outside our Firewall.)

Does anyone have any ideas how I can setup Workstation X to have internet access without being in our network (meaning Workstation X would not be able to view, browse, or ping anyone in the network)?

[Greenstead]

Just thingk aloud.

You could make his PC a different subnet with the router gateway.
But if he has admin rights he can change it back.

Or you could put zonealarm on each of your PCs and block everything but your own PCs, but you have to give them all static addresses then.

You can use a different workgroup name for your PCs. But he might find it out and change his to it.

Problem is, if he has admin rights it is hard to keep him out.

[kerpow]

What kind of equipment is this? An unmanaged switch, a Linksys Firewall etc. or professional Cisco (or similar) kit?

If it is the kind of stuff you buy in Best Buy, I'll agree that is quite difficult to keep him out short of setting up a server and forcing users to log onto a domain.

If it is Cisco equipment you can put filters on the swtich or firewall by MAC or IP addresses.