Windows 10 reached EOS (end of support) on October 14, 2025. If you are on Windows 10, see this article.

Avatar for Username

Rechercher dans l’assistance

Évitez les escroqueries à l’assistance. Nous ne vous demanderons jamais d’appeler ou d’envoyer un SMS à un numéro de téléphone ou de partager des informations personnelles. Veuillez signaler toute activité suspecte en utilisant l’option « Signaler un abus ».

En savoir plus

Ce sujet de discussion a été archivé. Veuillez poser une nouvelle question si vous avez besoin d’aide.

FF 39.0 with vanilla, new profile : DNS resolution fails even though system DNS works, thunderbird DNS works

  • 1 réponse
  • 1 a ce problème
  • 2 vues
  • Dernière réponse par tormen

tormen
tormen

System: GNU Linux, OpenSUSE 13.2 x86_64, kernel 4.1.3, firefox: i | MozillaFirefox | package | 39.0-34.2 | x86_64 | Main Update Repository


Hi.

I have a very strange problem: My notebook has internet (ip, dns and "ping www.av.com" works fine: p.ex. thunderbird works as expected).

But firefox tells me: Firefox can't find the server at www.av.com.

The nameserver in /etc/resolv.conf is 8.8.8.8, which is pingable and responds via "dig" (dig www.av.com @8.8.8.8). So this is not a network connection issue, no firewall issue.

All other programs can use internet. e.g. thunderbird keeps working as expected.

Just not firefox.

No special network settings in firefox. In particular : I had created a new vanilla firefox profil, so no addons.

Once I restart firefox, network is back. The problem is with DNS resolution, because pointing firefox to an IP (e.g. of www.av.com as returned by the above "dig") works as expected.

(also it is a fairly recent install, so I really think everything around firefox should be in perfect shape and order)

So far I noticed the problem seems to occur when changing wireless networks (e.g from home to work), which also includes a suspend.

But again: every aspect the system seems to be working fine, except for firefox that is not able to use the (new/changed) network connection anymore.

I found a somewhat similar problem that might be related: https://support.mozilla.org/en-US/questions/1049998

Can I debug any further ? Please feel free to give me any (very technical) task that can help you to debug this problem !

Otherwise I have no problem giving you remote ssh + XForward access to see the problem for yourself.

Thanks a lot for any hint.

Tormen

System: GNU Linux, OpenSUSE 13.2 x86_64, kernel 4.1.3, firefox: i | MozillaFirefox | package | 39.0-34.2 | x86_64 | Main Update Repository Hi. I have a very strange problem: My notebook has internet (ip, dns and "ping www.av.com" works fine: p.ex. thunderbird works as expected). But firefox tells me: Firefox can't find the server at www.av.com. The nameserver in /etc/resolv.conf is 8.8.8.8, which is pingable and responds via "dig" (dig www.av.com @8.8.8.8). So this is not a network connection issue, no firewall issue. All other programs can use internet. e.g. thunderbird keeps working as expected. Just not firefox. No special network settings in firefox. In particular : I had created a new vanilla firefox profil, so no addons. Once I restart firefox, network is back. The problem is with DNS resolution, because pointing firefox to an IP (e.g. of www.av.com as returned by the above "dig") works as expected. (also it is a fairly recent install, so I really think everything around firefox should be in perfect shape and order) So far I noticed the problem seems to occur when changing wireless networks (e.g from home to work), which also includes a suspend. But again: every aspect the system seems to be working fine, except for firefox that is not able to use the (new/changed) network connection anymore. I found a somewhat similar problem that might be related: https://support.mozilla.org/en-US/questions/1049998 Can I debug any further ? Please feel free to give me any (very technical) task that can help you to debug this problem ! Otherwise I have no problem giving you remote ssh + XForward access to see the problem for yourself. Thanks a lot for any hint. Tormen

Toutes les réponses (1)

tormen
tormen Auteur de la question

I just ran in the problem again. (this time just suspending, walking around and returning (and resuming) to the same wireless network)

I opened about:config. (all is at DEFAULT values, as I am with a freshly created new & vanilla profile!)

I toggled "network.dns.disablePrefetch" to be TRUE. I toggled "network.dns.get-ttl" to be TRUE.

I opened a new TAB : And *tada* DNS works.

So I think I just narrowed down the bug for you :) ;)

Please do not hesitate to get in touch with me to help rooting out this problem!