Unblock Firefox when Firefox is not working but IE is
by Sadik on 01/04/10 at 12:14 pm
My work takes me to different places, different offices. For the past few days I was working inside a network where for some inexplicable reason all browsers except internet explorer were blocked. All versions of IE were working just fine, but the network administrator through some firewall programme had blocked all other browsers.
I am surprised at how outdated this mentality is and how little some network administrators know about browser security. The rationale behind blocking all other browsers was that they did not want any “Non-Standard” software to run on their network. Ok, so it is not my position or place to judge them so I thought of what I can do to get my favorite browser back. Now, I absolutely love Firefox and I feel it is the best browser in the world. Google chrome is giving firefox good competition, but for advanced users who wanna raise hell with their browsers, Chrome is not there yet. It may be but not yet.
So coming back to the point, if you are under such a situation, what you want to do is make firefox report itself as a different user-agent to the network. In case you are interested in the technical jargon, here’s a quote from Wikipedia.
When a user agent operates, it typically identifies itself, its application type, operating system, software vendor, or software revision, by submitting a characteristic identification string to its operating peer. In the HTTP and SIP protocols, this is transmitted in a header field User-Agent.
User agents identify their software as part of the client-server conversation. In HTTP and SIP, the identity is transmitted via the
User-Agentrequest header, as described by RFC 1945. This string is then used by the communications partner to characterize the client and optionally select suitable content or operating parameters for session.
So in short, browsers or any applications that access network based services have to identify themselves. And that is how applications block browsers in the first place. So what you need to do is make firefox report itself as IE (or any other which is allowed) and you are good to go! So how we do it. Well… it’s firefox remember, did i tell you it was the best browser in the world? Well you install a simple Add-On, it’s called User Agent Switcher. Basically what it does is change the User-Agent header string and set it to default IE/other strings. So your network checks are spoofed into thinking it’s IE and allowing it to go! 
If you already are inside the prohibitive network and are wondering how you can install the addon in firefox, just open the add-on page from IE and right click on “Add to Firefox” and click on “Save Target As“. That will save a .xpi file on your computer. Now start firefox and Goto File–>Open File and open the .xpi file. That should start the Add-On install process. Once installed, restart firefox.
Now go to Tools menu in firefox and it will have an entry where it says “Default User Agent“. Just click on that and select Internet Explorer and then version.
Select User-Agent
So there you go, now your firefox is IE for the network and happy browsing.
P.S: If you are still using Internet Explorer simply because it comes installed by default, you are missing out on a rich internet browsing experience. Go get Firefox right now!
