How to Block Proxy Websites

Proxy sites are websites most commonly used to bypass internet circumvention. This can pose potential security threats to a network due to viruses and such being tunneled in past active security measures. Blocking these sites is often a desirable action  of IT professionals and network administrators.

1. 
   1
   Identify why you need to block proxy websites.  This will help you determine possible threats and what steps you may need to take to prevent them. This also helps you find the best option to handle the situation at hand.
2. 
   2
   Setup your security software. If you are in a network environment such as a school, work place or library all your network traffic should be going through a central point such as a server acting as a firewall or filter. Installing security software such as Bess will filter the web traffic and operate along your specifications. Setup for your software will vary among manufacturers but many offer the same features of allowing you to block to certain degrees and live updating from a blacklist.
3. 
   3
   Find a live updating blacklist of proxy sites. Several security companies offer this and provide a URL that can live update your security software and consistently block the most well known and many obscure proxies. Many software companies offer this built in but some are better than others. select the one that best fits your needs. This means less work for you and you don't have to constantly monitor network traffic to catch the security breaches.
4. 
   4
   Tweak your security software settings. Often times internet filtering programs are either too strict and block things that should be accessible, or are too lenient and allow too many things through. Try to find a good medium between a secure network and happy users. Briefly monitoring security logs for blocked sites and then editing your block lists is a good way to keep your network both secure and allow your users the internet assets they need. Another option is to get feedback from you users. While this is often not possible in large infrastructures in a face to face basis a comment or inquiry page is often a great way to keep an eye on how your users view the network and provide them with the best possible access.
5. Source: http://www.wikihow.com/Block-Proxy-Websites