On 2026-09-08 12:14:19 +0200, Nicolas George wrote: > Vincent Lefevre (HE12026-09-08): > > I could see with "dig" (so not using the resolver) that DNS requests > > sometimes fail with a SERVFAIL error (not just on joooj.vinc17.net, > > but on arbitrary hostnames, and this seems to be random). There are > > 2 nameservers in /etc/resolv.conf, and both are affected. > > Using dig does not show you the requests made by the applications.
I was using dig to see whether there were any issues with the nameservers. > But if the error is as glaring as a DNS resolver returning SERVFAIL, > then the result might be relevant. Normally, it shouldn't as both IPv4 and IPv6 addresses are cached on this machine. FYI, the behavior of getaddrinfo() is the following: At home, without nscd (correct): Family: AF_UNSPEC [IPv6] IP: 2001:4b99:1:3:216:3eff:fe20:ac98 (Port: 80) [IPv4] IP: 155.133.131.76 (Port: 80) Family: AF_INET [IPv4] IP: 155.133.131.76 (Port: 80) Family: AF_INET6 [IPv6] IP: 2001:4b99:1:3:216:3eff:fe20:ac98 (Port: 80) On the machine with the issue, reproducible every time: Family: AF_UNSPEC [IPv6] IP: 2001:4b99:1:3:216:3eff:fe20:ac98 (Port: 80) Family: AF_INET [IPv4] IP: 155.133.131.76 (Port: 80) Family: AF_INET6 [IPv6] IP: 2001:4b99:1:3:216:3eff:fe20:ac98 (Port: 80) even though the requests to the name servers with "dig" currently succeed all the time (I suppose that this will be the case until the TTL becomes 0). -- 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)
