1

All of a sudden, my server (Debian Buster) can no longer connect to DNSs. When I try nslookup, it fails:

$ nslookup www.google.com
;; connection timed out; no servers could be reached

I'm not exactly sure when this started, but I'm guessing it started yesterday at 9am exactly since that's also the time Munin stopped logging certain modules:

Munin Graphs

It's strange why munin stopped logging traffic for IP xxx.xxx.xxx.146 but not for xxx.xxx.xxx.147. Going through all the munin graphs, it stopped logging for about half the modules.

So any ideas how to troubleshoot this? A server reboot did not help.

Stuggi
  • 3,506
  • 4
  • 19
  • 36
Zippy1970
  • 247
  • 1
  • 4
  • 12
  • Have you checked that your DNS servers are still configured? cat /etc/resolv.conf is one place to look. – Stuggi Jun 03 '20 at 08:16
  • Oddly enough, none of the DNS servers I had listed in resolv.conf could be reached (tested with PING). I added 8.8.8.8 and now it can lookup domain names again, but the problem with munin remains. Half the modules suddenly stopped logging. – Zippy1970 Jun 03 '20 at 08:22
  • Ok, that sorts that out. Be aware however that there are multiple ways DNS resolvers are set in Debian these days, so you might have something on your box that sets them for you, and if that's the case, your changes in /etc/resolv.conf won't be persistent. – Stuggi Jun 03 '20 at 08:24

0 Answers0