Join the AMA (Ask Me Anything) with the Firefox leadership team to celebrate Firefox 20th anniversary and discuss Firefox’s future on Mozilla Connect. Mark your calendar on Thursday, November 14, 18:00 - 20:00 UTC!

This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Avatar for Username

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

This thread was archived. Please ask a new question if you need help.

slashdot.org loads slowly due to a.fsdn.com or DoH ?

  • 4 replies
  • 0 have this problem
  • 3 views
  • Last reply by jonzn4SUSE

Timothy
Timothy
more options

During an initial visit to slashdot.org Firefox hangs for approx 45 seconds while the status bar says "looked up a.fsdn.com." Subsequent visits during the same browser session load promptly.

This is with Preferences -> General -> Network Settings -> Enable DNS over HTTPS -> Cloudfare or NextDNS. With Firefox DoH disabled the problem is not present. [Interesting side, the machine's systemwide DNS settings are configured for Cloudfare 1.1.1.1 ]

AFAIK all other sites load normally. I've been using the Firefox DOH for several months with only the above site as a problem.

Ideas?

Environment: Firefox desktop 106.x and 107.x macOS 10.13.6 The problem is present in "Troubleshoot Mode" when Firefox DOH is enabled.

During an initial visit to slashdot.org Firefox hangs for approx 45 seconds while the status bar says "looked up a.fsdn.com." Subsequent visits during the same browser session load promptly. This is with Preferences -> General -> Network Settings -> Enable DNS over HTTPS -> Cloudfare or NextDNS. With Firefox DoH disabled the problem is not present. [Interesting side, the machine's systemwide DNS settings are configured for Cloudfare 1.1.1.1 ] AFAIK all other sites load normally. I've been using the Firefox DOH for several months with only the above site as a problem. Ideas? Environment: Firefox desktop 106.x and 107.x macOS 10.13.6 The problem is present in "Troubleshoot Mode" when Firefox DOH is enabled.

All Replies (4)

jonzn4SUSE
jonzn4SUSE
  • Top 10 Contributor
more options

My DNS is also 1.1.1.1 and the site loads in under a second for me. see screenshot Let me also try my mac running 10.13.6 Are you on WiFi or plugged in?

jonzn4SUSE
jonzn4SUSE
  • Top 10 Contributor
more options

No issue for me on my mac. see screenshot I'm on WiFi.

Modified by jonzn4SUSE

Timothy
Timothy Question owner
more options

jonzn4SUSE said
My DNS is also 1.1.1.1 and the site loads in under a second for me. see screenshot Let me also try my mac running 10.13.6 Are you on WiFi or plugged in?

Thanks for testing this. Are you using 1.1.1.1 via the Firefox native DoH settings? When I disable Firefox's native DoH and just use 1.1.1.1 systemwide the problem goes away. It happens even in a fresh Firefox profile. The issue doesn't happen in Chrome using its native DoH. I'm on WiFi.

jonzn4SUSE
jonzn4SUSE
  • Top 10 Contributor
more options

Yes, same setup.