How to block Websocket protocol (to simulate corporate firewalls) on Ubuntu?

Question

I am working on a web app that uses WebSockets, and I know that many corporate firewalls block it. Now I have added Socket.io to fallback to XHR polling in case Websockets are blocked.

But I can't figure out how to simulate this environment for testing. How can I simulate an environment similar to corporate firewalls?

I am on Ubuntu 12.04, but can switch to Windows 7 if required. Am open to any different approaches as well.

Answer 1

install squid and tell your browser to use it as a proxy.