Firefox Community Forum

Ever since upgrading to Windows 11, my Firefox installation has occasionally been unable to resolve domain names of some websites. Example domains:

• apps.powerapps.com
• static.cdninstagram.com
• google.com

As I was trying to debug this, I discovered that the DNS resolution and connection timings are just over 30 seconds (see the attached image). This is highly unusual.

• The issue does not occur with other web browsers on my computer (i.e., Microsoft Edge).
• The issue has persisted across reboots.
• I have already reinstalled Firefox (and wiped the temp files and appdata profile before installing again).
• The issue does not occur with other devices on my home network.
• DNS over HTTPS has been manually disabled.
• Changing DNS resolvers in my Windows settings does not fix the issue.
• The issue is still present with a fresh, unmodified installation of Firefox.

Any help would be greatly appreciated! I love Firefox and do not want to switch to a different browser.

I like the Firefox browser and Firefox was working fine for months but Firefox did ask me to do another update today. I did the update as requested and after the update Firefox will not connect to any websites on my desktop despite an excellent internet connection. I cannot find anyway to contact Firefox directly. For major problems such as a 100 percent failure rate to connect to any website, Firefox should provide direct help to the user as to the current major problem. I appreciate user ideas but Firefox should offer some help for major problems as the likely solutions can change over time. Hopefully if Firefox oversees user questions, someone at Firefox tech will at least respond to my question on this website or better yet contact me directly.

The problem may well be the update itself. The Firefox browser is working on my smartphone but not the desktop internet browser. I have some browser settings that I do not want to lose which a complete Firefox removal and reinstall would likely cause. Any suggestions from fellow Firefox users are appreciated and I look forward to them. Have other Firefox users experienced this major problem?

Thank you.

NOTE: I have marked this as "Solved" because I figured out the problem described below, and I fixed it. See my following message here for a description of my solution.

Original message starts here ...

I'm using Firefox 144.0 under Debian Linux. I've used Firefox on this machine for years with no problem. Firefox can easily connect to literally thousands of web servers on the internet, both via HTTP and HTTPS.

But now, I'm having an issue:

I started running a web server on the same machine that Firefox is running on. This server only listens for non-HTTPS connections on port 80. I am not using any proxy server with Firefox.

I can easily and directly connect to my local web server's pages from my local machine from Chrome, w3m, curl, and direct telnet connections to port 80 ... all of which are addressing the publicly accessible domain name for my local web server. However, However, Firefox refuses to connect to any URL's on my local machine, and it gives me the following explanation:

Unable to connect

Firefox can’t establish a connection to the server at [ my server's domain name ].

   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.

In Firefox, I have all auto-forcing of HTTPS disabled by means of Don’t enable HTTPS-Only Mode turned on.

I get the same error in Firefox whether I connect via a URL like "http://MYFULLDOMAINNAME" or a URL like "http://AAA.BBB.CCC.DDD", where "AAA.BBB.CCC.DDD" is my machine's publicly accessible static IP address and "MYFULLDOMAINNAME" is the long-standing, publicly accessible domain name for my machine ... both with and without a suffix of ":80" on the supplied URL.

And again, all other browsers on my machine have no problem whatsoever connecting to my own local web server on this same local machine of mine using those same URL's.

And all browsers (Firefox and otherwise) that are running on other machines all over the internet have no problem connecting to that same web server via the same URL's that I described above

Also, I have no firewall rules on my machine which would block access to my own machine's port 80.

What could be causing this error in Firefox, and what might I be able to do to fix it?

Thank you very much in advance.

UPDATE: Just a bit more information. Looking at the web logs, I see that Firefox's request never even reaches my local web server. In other words, Firefox itself is not even trying to make a TCPIP port 80 connection to my local web server in the first place

The connection has timed out

The server at eofficepwd.kerala.gov.in is taking too long to respond.

   * itemThe 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.

Hmm. We’re having trouble finding that site.

We can’t connect to the server at data.digital.costco.com.