On 2026-09-15 22:07:02 +0200, Marco Moock wrote: > Am 13.09.26 um 00:00 schrieb Vincent Lefevre: > > On 2026-09-12 01:09:06 +0700, Max Nikulin wrote: > > > On 10/09/2026 11:46 pm, Vincent Lefevre wrote: > > > > On 2026-09-10 10:00:16 +0700, Max Nikulin wrote: > > > > > On 10/09/2026 6:37 am, Vincent Lefevre wrote: > > > > > > this is because getaddrinfo returns > > > > > > only the IPv6 address. This is not a question of precedence. > > > > > > > > > > Do you see any benefits in disabling IPv6 on your machine? > > > > > > > > Disabling completely, apparently not. Disabling a part of it, such > > > > as SLAAC, yes, because in the past, some machines on the network > > > > sent fake RA advertising. My main personal machine on the network > > > > just has SLAAC disabled for this reason. > > > > BTW, on this point, disabling SLAAC is a bit complex. I thought that > > accept_ra = 0 was sufficient (at least when I added it in 2015), but > > it was actually ignored by NetworkManager, for which I had to add > > ipv6.dns-priority=-100 in its configuration several months ago. > > This doesn't disable SLAAC, but if that mitigates your problem, there is a > major problem - and it is not SLAAC neither IPv6.
I don't know whether this mitigates the problem on this machine. Then what do you suggest? > > > Thanks for clearly stating it. I asked, looking at the thread subject, > > > since > > > host name resolution to IPv6 addresses and IPv6 link configuration are > > > orthogonal to some degree and it is not immediately obvious. > > > > Note that I was not really complaining about the host name resolution > > to IPv6 addresses; but from their error message, I thought that some > > utilities (ping, wget...) tried an IPv6 connection without trying > > IPv4. > > As you refuse to show the output of "ip a", it is not possible to help here. Perhaps you should read the whole thread. I gave it last week: Date: Tue, 8 Sep 2026 18:48:17 +0200 From: Vincent Lefevre <[email protected]> To: [email protected] Subject: Re: How to prevent programs from using IPv6 by default on a machine without IPv6 support? Message-ID: <[email protected]> > nscd is not installed by default in Debian. Please show us the > configuration. # logfile /var/log/nscd.log # threads 4 # max-threads 32 # server-user nobody # stat-user somebody debug-level 0 # reload-count 5 paranoia no # restart-interval 3600 enable-cache passwd yes positive-time-to-live passwd 600 negative-time-to-live passwd 20 suggested-size passwd 211 check-files passwd yes persistent passwd yes shared passwd yes max-db-size passwd 33554432 auto-propagate passwd yes enable-cache group yes positive-time-to-live group 3600 negative-time-to-live group 60 suggested-size group 211 check-files group yes persistent group yes shared group yes max-db-size group 33554432 auto-propagate group yes enable-cache hosts yes positive-time-to-live hosts 3600 negative-time-to-live hosts 20 suggested-size hosts 211 check-files hosts yes persistent hosts yes shared hosts yes max-db-size hosts 33554432 enable-cache services yes positive-time-to-live services 28800 negative-time-to-live services 20 suggested-size services 211 check-files services yes persistent services yes shared services yes max-db-size services 33554432 enable-cache netgroup yes positive-time-to-live netgroup 28800 negative-time-to-live netgroup 20 suggested-size netgroup 211 check-files netgroup yes persistent netgroup yes shared netgroup yes max-db-size netgroup 33554432 > nscd offers options for caching negative responses. Which values are set > here? See above. > > > However does libc really performs retry when it gets SERVFAIL, not > > > timeout? > > > > There doesn't seem to be any retry (this would be useless anyway > > in my case). > > > > > Again, if you are saying that without AAAA query resolver reliably gets > > > IPv4 > > > addresses, it might be an approach. By the way, resolv.conf(5): > > > > > > options > > > no-aaaa (since glibc 2.36) > > > > Interesting to know. I'll suggest that to the admin. > > Another shitty idea, as this doesn't address the real issue. Just my 2 > cents. So what do you suggest? -- Vincent Lefèvre <[email protected]> - Web: <https://www.vinc17.net/> 100% accessible validated (X)HTML - Blog: <https://www.vinc17.net/blog/> Work: CR INRIA - computer arithmetic / Pascaline project (LIP, ENS-Lyon)
