openDNS allow a network administrator to block or limit what sites or types of sites (via categories) a user of the network can access. Setup is quick and simple. Simply signup for an openDNS account and then update your router with their IP addresses – 208.67.222.222 and 208.67.220.220
Once you’ve signed in, you can setup shortcuts, stats and blocks. Not only can you limit what sites people can visit, you can also view stats on how many times people on your network have tried to access those blocked sites. Although you can’t pinpoint which exact computer on your network was trying to reach the blocked domain.
To prevent your users from circumventing the blocks, you’ll want to apply firewall rules in your router that restrict any TCP/UDP traffic on port 53 to be redirected to openDNS. If you have an advanced router which is capable of deep packet inspection then you could also make use of this to ensure DNS packets only ever go to openDNS and not to another public DNS server which wouldn’t enforce your restrictions.
Another way that users of your network may try to bypass openDNS is via a VPN or web proxy. Thankfully openDNS have a category for web proxies that will block the proxies as fast as they pop up. As for VPN, again you can use firewall rules on your router to prevent people bypassing the opendns blocks.