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Firefox desktop on Ubuntu and Windows says "server not found" trying to connect to cdc.gov!

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  • 1 has this problem
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  • Last reply by aboba0

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Running Firefox on Ubuntu 20.04, Windows 10, and Android 11. versions 83.0, 83.0, and 83.1.0 respectively.

As of 12/10/2020 discovered that on Ubuntu 20.04 Firefox would not get to cdc.gov and gave message "server not found".

On 12/11/2020 I started digging a bit deeper.

  • Firefox on the Ubuntu and Windows hosts, both on home WiFi (Optimum, public IP 24.47.128.216) does not get to cdc.gov with message "server not found".
  • Firefox on Android 11 (WiFi connected and LTE at 3 bars) does connect to cdc.gov. Don't know how to tell if connection via WiFi or LTE.
  • Firefox on Ubuntu and Windows hosts using USB tethering to phone for Internet does not connect to cdc.gov.
  • Chrome 87.0.4280.88 and Chromium 87.0.4280.88 on Ubuntu and Windows hosts on home WiFi connect to cdc.gov
  • Edge 87.0.664.60 on Windows host on home WiFi connects to cdc.gov

Seems Firefox desktop for Ubuntu and Windows is having some kind of problem with cdc.gov. Have tried running in Safe Mode and selecting Restart with add ons disabled and Refresh Firefox. Neither option has resolved problem.

What's wrong?

Running Firefox on Ubuntu 20.04, Windows 10, and Android 11. versions 83.0, 83.0, and 83.1.0 respectively. As of 12/10/2020 discovered that on Ubuntu 20.04 Firefox would not get to cdc.gov and gave message "server not found". On 12/11/2020 I started digging a bit deeper. * Firefox on the Ubuntu and Windows hosts, both on home WiFi (Optimum, public IP 24.47.128.216) does not get to cdc.gov with message "server not found". * Firefox on Android 11 (WiFi connected and LTE at 3 bars) does connect to cdc.gov. Don't know how to tell if connection via WiFi or LTE. * Firefox on Ubuntu and Windows hosts using USB tethering to phone for Internet does not connect to cdc.gov. * Chrome 87.0.4280.88 and Chromium 87.0.4280.88 on Ubuntu and Windows hosts on home WiFi connect to cdc.gov * Edge 87.0.664.60 on Windows host on home WiFi connects to cdc.gov Seems Firefox desktop for Ubuntu and Windows is having some kind of problem with cdc.gov. Have tried running in Safe Mode and selecting Restart with add ons disabled and Refresh Firefox. Neither option has resolved problem. What's wrong?

Chosen solution

Seems to be working fine now with DoH enabled, but less than an hour ago this still didn't work for me, so this was fixed quite recently on the Cloudflare DNS server.

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This can be a problem with using DNS over HTTPS. cdc.gov redirects to www.cdc.gov and the DNS Lookup tool on about:networking can't resolve this domain when using the Cloudflare server.

You can try to disable DoH to check if that makes the CDC website load. You may have to close and restart Firefox after toggling DoH via "Options/Preferences -> General -> Network Settings".


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Chosen Solution

Seems to be working fine now with DoH enabled, but less than an hour ago this still didn't work for me, so this was fixed quite recently on the Cloudflare DNS server.

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Thought I had a screenshot to share but can't find it now.

What I put in address bar was cdc.gov. Am pretty sure the URL in the screenshot was https://www.cdc.gov. So it seems the redirect was working. But I wasn't getting to the site. Which I think correlates to what you've said. The redirect happens but the new name isn't resolved.

Moot now. cdc.gov and www.cdc.gov both get to the site.

Thanks.