Connect to a Server
If you have a problem connecting to a website, you may see error messages like Server Not Found. This article describes how to troubleshoot problems that cause this error.
To begin, try opening a website in another browser (such as Internet ExplorerSafariEpiphany or Chromium).
If neither Firefox nor your other browser can load websites, your problem is not in Firefox, so you should seek help elsewhere.
You should also check the following:You should begin by checking the following:
- Make sure your modem and/or router are both on and are not indicating errors.
- If you are using a wireless connection, make sure that you are connected to the right access point.
- Make sure your Internet security software (including firewalls, antivirus programs, anti-spyware programs, and more) is not blocking connections to the Internet. For instructions on how to configure these programs, see the Configure firewalls so that Firefox can access the Internet article.
- If you use a proxy server, make sure that the proxy server can connect to the Internet. For instructions on configuring proxy settings in Firefox, see below.
If Firefox cannot load websites, but your other browser can, follow the instructions below.
Cannot load websites after updating Firefox
If you were able to load websites until you updated Firefox, your Internet security software (including firewalls, antivirus programs, anti-spyware programs, and more) is likely preventing Firefox from connecting to the Internet. Some Internet security programs can block Internet access even when they are in a "disabled" state.
In general, you should remove Firefox from your program's list of trusted or recognized programs, then add it back. For instructions on how to configure these programs, see the Configure firewalls so that Firefox can access the Internet article.
Firefox connection settings
If you connect to the Internet through a proxy server that is having connection problems, you will not be able to load websites. To check your Firefox proxy settings:
- Click the menu button and choose Options.Preferences.
- Select the panel.
- Select the Network tab.
- In the Connection section, click Settings.
- Change your proxy settings:
- Click OK to close the Connection Settings window.
- Close the about:preferences page. Any changes you've made will automatically be saved.
In the address bar, type about:config and press EnterReturn.
- The about:config "This might void your warranty!" warning page may appear. Click I'll be careful, I promise!I accept the risk! to continue to the about:config page.
- Right-clickHold down the Ctrl key while you click in the list of preferences, select, and then select .
- In the Enter the preference name window, enter network.dns.disablePrefetch and click OK.
- Select true when prompted to set the value and click OK.
- In the FilterSearch field, type network.dns.disableIPv6
- In the list of preferences, double-click network.dns.disableIPv6 to change its value from false to true.
If you find that Firefox can load some websites but not others, first clear your Firefox cookies and cache:
- Click the menu button , choose History and select .
- In the Time Range to clear: drop-down, select Everything.
- Click the arrow next to Details to display the list of items that can be cleared.
- Select both Cookies and Cache.
- Click Clear Now.