If there are any Catalyst switches located withhin the catchment areas, or in his area, I would suggest putting the guy's sever on a VLAN. However, Cisco 2500 routers can be purchased on Ebay cheaply now. Range of 250-400. I would invest in a Cisco 2500 router, get the latest IOS, and install some extended ACLs. That should be all the security the guy needs, as long as the system is fairly secure. Either do this or invest in what super_phreak had to offer up above^, it seemed like a good bet also.