Google
 

Sunday, October 5, 2008

Firefox cannot access internet / Other web-browsers e.g. IE can / Firefox cannot access internet after update / Firefox “network timeout” error.


After I myself faced a series of connectivity issues with Firefox I thought of writing this blog. This will hopefully summarize some of the many solution approaches to fix the problem.


When Firefox opens, mostly it gives the following message:

Unable to connect

Firefox can't establish a connection to the server at forums.mozillazine.org.

* The site could be temporarily unavailable or too busy. Try again in a few moments.

* If you are unable to load any pages, check your computer's network connection.

* If your computer or network is protected by a firewall or proxy, make sure that Firefox is permitted to access the Web.



This can happen due to many reasons:

  • Your browser may have been hijacked by spywares, adwares, or other such malwares.

  • Due to plugin errors, incompatible themes or clash with a third party software.

  • Severe corruption in Windows registry.

  • Firefox installation might have got corrupted somehow.

  • Due to virus attack.

  • Incorrect proxy settings.

  • Due to modification done in the windows host file

  • Crashed TCP/IP.

  • Misconfigration in the firewall.

  • Firewall that recognizes that Firefox restricts it silently even if it is disabled.

  • Sometimes this problem appers if the firewall is not uninstalled correctly.

  • Besides this there can be many other reasons (covered below).


Before trying out the various approaches, make sure that your Internet connection is working properly working. To find this:

Open a DOS command window [Run → cmd] and try pinging the google website. Ex:

C:\>ping www.google.com

A successful ping request will verify that a computer's network interface card, it's drivers, and the operating system's TCP/IP implementation are all functioning correctly. In brief it checks if network connections are intact.

Once you are sure that your connection is fine, you can proceed.

Some of the common Firefox connection issues with their resolutions are stated as under:-

  1. Incorrect Proxy settings

The most common problem observed is due to incorrect proxy settings. If you using a proxy service and that you are able to connect/browse from IE, then this can most likely be causing the problem. In such a case make sure that the IE proxy settings match to that of Firefox proxy settings.

In IE go to:

Tools menu -> Internet Options -> Connections -> LAN Settings

In Firefox it’s in:

Tools menu -> Options -> Advanced -> Network -> Settings button in the connections section

(If the settings vary, then copy-paste the proxy settings info, from IE to Firefox)

Now restart Firefox.



  1. Try flushing Windows DNS cache

    If repeated attempts fail to open a website, Windows may have cached an unsuccessful DNS lookup attempt. This means that you may not be able to view a particular website until the cached result expires. As a workaround, you can flush the DNS cache then try loading the site again.

  • Start -> Run -> type cmd

  • ipconfig/displaydns and press Enter (this will display DNS info)

  • now in command prompt, type ipconfig /flushdns and press Enter (this will clear the DNS info)

  • Now restart Firefox and check if it works.



  1. Clear Firefox’s own internal cache

  • open Firefox -> Tools -> Clear Private Data (Check the cache) and click “Clear Private Data Now

  • Now restart Firefox and check if it works.



  1. Firefox may still be working in “offline mode”.

To turn off offline mode:

  • Uncheck this option from File menu -> work offline

  • Now restart Firefox.



  1. Problem due to persistent connections.

We can disable this in the following way:

  • Open a new tab, type: about:config, press Enter

  • Click "I'll be careful, I promise!"

  • Search for the value: network.http.keep-alive

  • Right click on this value and click "toggle" to change it to false

  • Restart Firefox



  1. Due to third party tools e.g. Firewalls, Security Suites, etc. / Due to ‘up-gradation of these Security Utilities’ / Due to ‘Up-gradation of Firefox’ in presence of any security software can cause such problems.

  • Often downgrading Firefox (Say, if prior to its upgrade it was working) to previously installed version solves the problem.

  • Uninstall “completely” any security software e.g. Norton firewall, Zone Alarm Firewall, etc. as this may be blocking Firefox.

  • If you are still keeping such security suites, then check the permissions given to Firefox in your firewall settings. See that it’s not restricted. Else, you must reconfigure the firewall to permit access to Firefox.

  • If un-installation of security suites doesn’t work, then there can be a possibility that the un-installation still has some leftovers. To find this:

    Once you have removed such processes then try to open Firefox.


  1. If connection settings are not remembered

Certain software may be is overriding your connection settings. To remove the override:

  • Open the profile folder, in “../program files/Mozilla firefox”

  • Open the user.js file for editing.

  • If there is no user.js file, you don't have any overriding settings, so this isn't the problem.

  • Remove any lines that have the word "proxy" in them.

  • Save the file.

  • Restart Firefox



  1. Problem due to Ipv6

Firefox uses IPv6 by default. You can disable IPv6 and see if it helps.

  • In the url, type about:config, and press EnterReturn. Then click “I'll be careful, I promise!”

  • Search network.dns.disableIPv6

  • If the value is false, double-click on it, to change the value to true.

      If the value is already true, IPv6 is already disabled, so it isn't causing your problem.”

  • Close and restart Firefox

    If disabling IPv6 doesn't resolve the problem, re-enable IPv6 by setting the preference back to false.



  1. Clean install Firefox

  • Uninstall Firefox completely.

  • Delete any leftovers in ‘../Program files/’ folder, i.e. delete the folder ‘Mozilla Firefox’ from there.

  • Clean the windows registry using a good registry cleaner.

  • Reinstall Firefox, and try again.



  1. Many times viruses corrupt the registry settings causing Firefox not to operate correctly.

  • For this use a good scanner. You can try scanning with the following:

    • Kaspersky Anti-virus

    • PC Tools Spyware doctor

    • Spybot Search and Destroy

  • If viruses/adware/etc. are detected. Then after removing, you must clean the registry.

  • After this, go ahead with a fresh installation of Firefox.

  • Also, perform steps as in #11. (See below)



  1. Spyware/viruses can cause to malform LSP or corrupt TCP/IP and/or Winsock registry entries.

  • To solve the problem download the utility “XP TCP/IP Repair”.

  • Do the repairing with it and restart system to take effect.

    This is a very important fix that one must try.


12. Issues in customization and preferences.

  • Start Firefox in Safe Mode.

  • "Firefox Safe Mode" window appears, containing some troubleshooting options. Check the boxes, "Reset toolbars and controls" (this is to remove any toolbar customizations) and "Reset all user preferences to Firefox defaults" (this will remove any user-set preferences and restores the default theme).

  • Next, press the button, "Make Changes and Restart".


13. Extension and theme issues

    Sometimes its all due to a problematic extension. Start Firefox in Safe Mode.

    When the "Firefox Safe Mode" window appears, press the button, "Continue in Safe Mode". (This will start the program with all extensions disabled and with the default theme.)

    If the problem goes away in Safe Mode:

  • Update or uninstall the added theme or select the default theme in "Tools → Add-ons → Themes".

  • Update or selectively disable or uninstall your added extensions in "Tools → Add-ons → Extensions"


14. Due to windows HOST file

    A special Windows file called the "Hosts" file and its use to control Internet browsing.You can find this in the folder \Windows\system32\drivers\etc\, with the name "hosts.sam". A hosts file has the ability to redirect Internet requests.

    These host files sometime gets modified due to viruses and this can effect our browsing.

    Review your hosts file to see if it contains any entries other than 127.0.0.1 localhost. If it does, then make the necessary editing.

    The orignal windows host file looks likes this:

    You can google up and find more information regarding how to edit a host file.

14 comments:

Nickname unavailable said...

Hi, thanks for posting your guide! Unfortunately it did not help me. My problem does not seem to be with just Firefox. IE and Opera are all the same (though Opera is more likely to open a page at the moment). I have trawled the web all week trying to find the problem - and the solution. I'd appreciate any further advice you can give.

PVaish said...

does any one have the solution to this problem? I have tried with no success. My laptop van not go to any site using any browser including IE, firefox, safasri as well as chrom.

itunes, outlook etc contnue to work. i can ping sites. dnskookup resolve the sites as well.

Barbara said...

Thanks for the helpful suggestions. I found that in IE my proxy settings had the box ticked to use the same proxy settings for all protocols. When I checked "Use this server for all protocols" in Firefox. I could once again browse the sites that previously timed out.

Gregor Samsung said...

Hi, thanks for your effort! Here's my problem: i can access the net with IE8, but not with either Firefox or Chrome. Furthermore, when i do try to ping www.google.com, i get no response even though IE accesses google with no problems.
Do you have any idea what this might be due to?
Thanks
Gianluca

Saravanan said...

Seems you are using firewall. It is blocking the site.

I had a similar kind of issue for past one week. Then I've disabled the firewall in modem and now it is working fine. Please ask your ISP providers for more details.

Regards
Sarav

Saravanan said...

Seems you are using firewall. It is blocking the site.

I had a similar kind of issue for past one week. Then I've disabled the firewall in modem and now it is working fine. Please ask your ISP providers for more details.

Regards
Sarav

sideways said...

Hi, Thanks very much to "whoever" ticking use this proxy for all protocols and adding the hotmail.com non valid cert into the exception list did the trick, "awsome"

Cheers :-))

Lovely Anne said...

hi! i'm having a problem accessing the peoplefinders site. i need this for my online job. although i do not have any problems with other sites, just the peoplefinders. is this a problem with my computer or my internet connection? what should i do to solve this problem?

vishal said...

Easy Earning money in online never been this easy and transparent. You would find great tips on how to make that dream amount every Day. Sitting in the home earn around $100 per day. So go ahead and click here for more details and open floodgates to your online income. All the best.

Thanks.

vishal said...

Easy Earning money in online never been this easy and transparent. You would find great tips on how to make that dream amount every Day. Sitting in the home earn around $100 per day. So go ahead and click here for more details and open floodgates to your online income. All the best.
Thanks.

DonA said...

Hey i want to access one website but it always saying this.
Server not found







Firefox can't find the server at www.tube8.com.





Check the address for typing errors such as
ww.example.com instead of
www.example.com
If you are unable to load any pages, check your computer's network
connection.
If your computer or network is protected by a firewall or proxy, make sure
that Firefox is permitted to access the Web.

Network Consultant said...

I experienced this before that I cannot open some websites, even my email. I taught its the end of the world, my pc got broken well in fact I just bought it last week. Thanks to my friend who help me in solving this kind of issue. :)
Firewall Security Consulting NY

aalia lyon said...

That’s a nice blog , this blog helps you, please check this url and solve your windows 7 related problem.
windows firewall error 1068 windows 7
Thanks
Aalia lyon

Alex Gold said...

Thanks. you solve my problem easily!!! .Related issues visit this website Firefox Support and Call +1-800-296-4296 USA (Toll Free).