Am Sat, 6 May 2017 14:22:21 +0200 schrieb Kai Krakow <[email protected]>:
> Am Fri, 5 May 2017 20:18:41 +0200 > schrieb Lennart Poettering <[email protected]>: > > > On Fri, 05.05.17 01:01, Kai Krakow ([email protected]) wrote: > > > > > Hello! > > > > > > Why is systemd-resolved switching DNS servers all day long? This > > > doesn't seem to be right... > > > > If you turn on debug logging, you should see an explanation right > > before each switch. I figure we should choose the log levels more > > carefully, so that whenever we switch we also log the reason at the > > same level... > > It looks like this all has to do with timeouts: Fixed by restarting the router. The cable modem seems to be buggy with UDP packets after a lot of uptime: it simply silently drops UDP packets at regular intervals, WebUI was also very slow, probably a CPU issue. I'll follow up on this with the cable provider. When the problem starts to show up, systemd-resolved is affected more by this than direct resolving. I don't know if there's something that could be optimized in systemd-resolved to handle such issues better but I don't consider it a bug in systemd-resolved, it was a local problem. Thanks, Kai > Mai 06 14:17:09 jupiter systemd-resolved[5585]: Cache miss for > ssl.gstatic.com IN AAAA Mai 06 14:17:09 jupiter > systemd-resolved[5585]: Transaction 54375 for <ssl.gstatic.com IN > AAAA> scope dns on enp5s0/*. Mai 06 14:17:09 jupiter > AAAA> systemd-resolved[5585]: Using feature level UDP for transaction > AAAA> 54375. Mai 06 14:17:09 jupiter systemd-resolved[5585]: Using > AAAA> DNS server fe80::b248:7aff:fee7:f438%2 for transaction 54375. > Mai 06 14:17:09 jupiter systemd-resolved[5585]: Sending query packet > with id 54375. Mai 06 14:17:09 jupiter systemd-resolved[5585]: > Timeout reached on transaction 33004. Mai 06 14:17:09 jupiter > systemd-resolved[5585]: Retrying transaction 33004. Mai 06 14:17:09 > jupiter systemd-resolved[5585]: Switching to DNS server > 2a02:8109:1ec0:6f5:5667:51ff:feea:385f for interface enp5s0. Mai 06 > 14:17:09 jupiter systemd-resolved[5585]: Cache miss for > ssl.gstatic.com IN A Mai 06 14:17:09 jupiter systemd-resolved[5585]: > Transaction 33004 for <ssl.gstatic.com IN A> scope dns on enp5s0/*. > Mai 06 14:17:09 jupiter systemd-resolved[5585]: Using feature level > UDP for transaction 33004. Mai 06 14:17:09 jupiter > systemd-resolved[5585]: Using DNS server > 2a02:8109:1ec0:6f5:5667:51ff:feea:385f for transaction 33004. Mai 06 > 14:17:09 jupiter systemd-resolved[5585]: Sending query packet with id > 33004. Mai 06 14:17:09 jupiter systemd-resolved[5585]: Processing > incoming packet on transaction 33004. (rcode=SUCCESS) Mai 06 14:17:09 > jupiter systemd-resolved[5585]: Not validating response for 33004, > used server feature level does not support DNSSEC. Mai 06 14:17:09 > jupiter systemd-resolved[5585]: Added positive unauthenticated cache > entry for ssl.gstatic.com IN A 143s on > */INET6/2a02:8109:1ec0:6f5:5667:51ff:feea:385f Mai 06 14:17:09 > jupiter systemd-resolved[5585]: Transaction 33004 for > <ssl.gstatic.com IN A> on scope dns on enp5s0/* now complete with > <success> from network (unsigned). Mai 06 14:17:09 jupiter > systemd-resolved[5585]: Sending response packet with id 42127 on > interface 1/AF_INET. Mai 06 14:17:09 jupiter systemd-resolved[5585]: > Sending response packet with id 22131 on interface 1/AF_INET. Mai 06 > 14:17:09 jupiter systemd-resolved[5585]: Processing incoming packet > on transaction 54375. (rcode=SUCCESS) Mai 06 14:17:09 jupiter > systemd-resolved[5585]: Not validating response for 54375, used > server feature level does not support DNSSEC. Mai 06 14:17:09 jupiter > systemd-resolved[5585]: Added positive unauthenticated cache entry > for ssl.gstatic.com IN AAAA 203s on > enp5s0/INET6/fe80::b248:7aff:fee7:f438 Mai 06 14:17:09 jupiter > systemd-resolved[5585]: Transaction 54375 for <ssl.gstatic.com IN > AAAA> on scope dns on enp5s0/* now complete with <success> from > AAAA> network (unsigned). Mai 06 14:17:09 jupiter > AAAA> systemd-resolved[5585]: Freeing transaction 33004. Mai 06 > AAAA> 14:17:09 jupiter systemd-resolved[5585]: Sent message > AAAA> type=method_return sender=n/a destination=:1.352 object=n/a > AAAA> interface=n/a member=n/a cookie=234 reply_cookie=2 error=n/a > AAAA> Mai 06 14:17:09 jupiter systemd-resolved[5585]: Sent message > AAAA> type=method_call sender=n/a destination=org.freedesktop.DBus > AAAA> object=/org/freedesktop/DBus interface=org.freedesktop.DBus > AAAA> member=RemoveMatch cookie=235 reply_cookie=0 erro Mai 06 > AAAA> 14:17:09 jupiter systemd-resolved[5585]: Got message > AAAA> type=method_return sender=org.freedesktop.DBus > AAAA> destination=:1.273 object=n/a interface=n/a member=n/a > AAAA> cookie=181 reply_cookie=235 error=n/a Mai 06 14:17:09 jupiter > AAAA> systemd-resolved[5585]: Freeing transaction 54375. > > I just don't unterstand why, because all these nameservers work > perfectly well when used directly and not through the stub resolver. -- Regards, Kai Replies to list-only preferred. _______________________________________________ systemd-devel mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/systemd-devel
