There are several ways to do this. The easiest way is to have a router that includes a URL filtering service. That way, you control which pages you allow/deny at the exit point of your network. However, if you prefer to do this function with a server, you would need to load proxy software or other filtering service on that server. In this example, if you run proxy services, you can use one NIC. However, you would have to block all outbound traffic on the firewall for every node except the proxy server. Then force your clients to use the proxy server for internet access.
Alternatively, you could set up the server with two NICs with RRAS enabled. Then the workstations would use the server as their default gateway. Run the proxy/filtering software in the same manner. This method does not require you to configure your clients to use a proxy server. The proxy server just intercepts the traffic on the way out.
Again, always keep things as simple as possible. i would suggest hte interner router with URL filtering capabilities. It will be much faster than a dedicated server, and much less complicated, and cost less (no Windows license required, no proxy software needed, etc...)
JorgeM
Industrious Poster
4,016 posts since Dec 2011
Reputation Points: 294
Solved Threads: 545
Skill Endorsements: 115
you can block with a dns server, but it's an all or nothing situation. create a new dns zone and just put for example: facebook.com and it will forward those requests to your server. At my office i use a high end firewall and filter by IP addresses, but not a cheap solution with what you already have.
RTFMID10T
Junior Poster in Training
80 posts since Mar 2012
Reputation Points: 17
Solved Threads: 9
Skill Endorsements: 0