Even a content filtering product is deployed in your network, some experienced users still can bypass the content filter via proxies.

There are three kinds of proxies:

1). Proxy server

Proxy server provides proxy service for applications to access internet via proxy protocol, including HTTP, FTP., SSL and SOCKS proxy. SOCKS protocol description

2). Proxy Website

A proxy site is a web page which allows you to browse your favorite web sites – even though your access to those web sites might be blocked by a content filter.

3). VPN tunnel service

Online VPN service, for example: tor. Please check this blog for how to block tor.

In this tutorial, I will guide you to block proxy servers and proxy websites.

1. How to block proxy servers?

We can block proxy servers simply by block proxy protocol, such as HTTP, SOCKS.

2 Block proxy websites

2.1 Using website black list to block proxy sites

You can add proxy websites to a website black list to be blocked.

However, since a website black list can not contain all proxy websites, we recommend you to enable “URL keywords filtering” and “Web access rules” to block proxy websites based on our URL database and URL keywords.

2.2 Using URL keywords to block proxy sites

Add “proxy”, “unblock” to “Proxies”. So URLs with certain keywords will be blocked.

2.3 Using “Web access rules” to block proxy sites

Websites in “Proxies” category will be blocked. WFilter already has a default URL database which contains most common websites.

Many people might eager to know how to block PPS in their network. Because their roommates or family members eat up their bandwidth by using PPS. And the reason why it is hard to block PPS is it can use any random port.

What is PPStream?

PPS (PPStream) is a Chinese peer-to-peer streaming video network software. Since the target user is in Chinese mainland, there is no official English version, and bast majority of channels are from Eastern Asia, mostly Mainland China, Korea, Japan, Hong Kong, Taiwan and Singapore. Channel varieties vary from Chinese movies to Japanese anime, sports channels, as well as American popular TV and films.

It broadcast TV programs stably and smoothly to broadband users. Compared to traditional stream media, PPStream adopts P2P-streaming technology and supports high-volume traffic with tens of thousands of users online at once.

Brief introduction of PPStream protocol

How to block PPStream with the help of WFilter?

1. You need to block to block UDP ports 1024-65534 in your router or firewall.

2. Add a blocking level and enable “Block PPS”.

3. Apply blocking level to the computers you want to block.

4. Blocking events in WFilter.

Check PPStream blocking video at: http://www.youtube.com/watch?v=U2RbOgUEaDQ

You can find how to block P2P traffic and downloading at: How to block P2P traffic and downloading?