Firefox asks for proxy details, but only when accessing facebook

At work, all requests are forwarded to a central load-balancing, caching Squid proxy server. If I try to access Facebook from within Firefox, I get the standard proxy authentication dialog:

The proxy moz-proxy://<IP addresss> is requesting a username and password. 
The site says: "moz-proxy://<IP Address>"

However, this dialog comes only for facebook & only when accessed from Firefox - any clues as to why this happens? Accessing from Internet Explorer or Chrome works fine, and yes Facebook is not blocked.

Just Firefox gives this problem. I have installed NTLM Auth for Firefox addon, but it hasn't helped.

The proxy settings are set to auto detect, same as in Internet Explorer & Chrome.

I'm using the current stable version of Firefox, 10.0.2 on Windows XP SP3

Sathyajith Bhat

Posted 2012-03-09T06:02:56.080

Reputation: 58 436

@Sathya: Perhaps they are attempting to block Facebook? Hear if it also happens for other employees using Firefox (as I suppose hearing at the IT administrator if the company's policy has changed is kind of not what you want to be doing). – Tamara Wijsman – 2012-03-09T07:07:21.163

@TomWijsman it isn't blocked - I've mentioned it works fine on IE & Chrome. – Sathyajith Bhat – 2012-03-09T07:09:28.260

@Sathya: Strange that it only happens in Firefox though, you might get around using IE Tab. (Please note that there are multiple IE Tab add-ons and I'm unsure which is the right one or which works...)

– Tamara Wijsman – 2012-03-09T07:11:06.027

And this is only happening on a single computer? – iglvzx – 2012-03-09T07:26:56.630

@iglvzx it's my work system - I don't have other systems to test it out – Sathyajith Bhat – 2012-03-09T07:31:21.337

Can you edit your question to include your Connection Settings? chrome://browser/content/preferences/connection.xul ... If you have it set to manual, you can obscure any sensitive info, of course! – iglvzx – 2012-03-09T07:41:07.597

Answers

Most probably, your proxy is blocking the WebSocket protocol. Chrome before version 14 and IE don't support it, so they are not affected.

Go to the URL about:config, search for the key network.websocket.enabled and switch it to false.

mcortese

Posted 2012-03-09T06:02:56.080

Reputation: 166

1This worked for me, FF 14.0.1. problem was specifically with stackoverflow.com! – Christopher Mahan – 2012-08-21T22:19:38.140

Hoorah! This has fixed my problem, at last I can use stackoverflow without having to resort to IE! Thanks! – Dave Richardson – 2012-10-15T08:31:34.897

I Just tried the suggestion in the accepted answer and I'm afraid it didn't fix my problem, as well as these other suggestion which also didn't work: http://nasarabna.wordpress.com/2010/03/03/firefox-keeps-prompting-for-proxy-authentication/ (These solutions may be currently outdated)

However, while browsing the aboug:config page I found this entry:

signon.autologin.proxy

If this is set to TRUE the prompt does not appear anymore.

BTW: It does only work if you log in at least once. If you cancel it, it keeps appearing.

And, as a consequence, if you use the private browsing feature (I use it at work, for personal stuff: e-mail, etc.), every time you start a new private session you have to accept the login prompt. Not a big problem though...

Carles Sala

Posted 2012-03-09T06:02:56.080

Reputation: 131

I've been having the same issue for a while now. It's a bug specific to Firefox, and only when accessing Facebook addresses through a proxy. This page itself, for instance, brings up the dialog a total of 10 times, taking 10 clicks before I can dismiss it and go about my business.

I have since downgraded to Firefox 4.0.1, which fixed the issue. It's not a great workaround, but it's there.

EDIT: It turns out that last bit was premature - I've now started experiencing the same problem on 4.0.1.

jcarter

Posted 2012-03-09T06:02:56.080

Reputation: 21

Facebook: "We're on to you, jcarter!" :P – iglvzx – 2012-04-10T00:53:50.090

This problem is quickly driving me insane - what's worse is that Chrome flatly refuses to install on this machine, so don't have the option of using it in the interim. – jcarter – 2012-04-10T01:06:53.800

Which operating system? If Windows, you can try Google Chrome Portable.

– iglvzx – 2012-04-10T01:13:47.427

Thanks, that fixed the installation problem, but I still have a persistant issue with Chrome where it becomes stuck "Sending request..." and never loads the page. That's a story for another SU question though. – jcarter – 2012-04-10T03:26:54.280

Firefox 8 added Origin tag for images, which has caused some specific proxy issues. If Facebook works for you with Firefox 7, I would say it's a bug in Firefox.

eis

Posted 2012-03-09T06:02:56.080

Reputation: 1 851