For several days now, after several reboots I still am faced with the issue of my CentOS 7 machine not being able to ping my domain.

[root@ip126 ~]# ping sub.mydomain.eu
ping: sub.mydomain.eu: Name or service not known

How am I able to clear whatever cache is preventing me from connecting to this address?

  • You cannot ping a domain; is that a domain name or a host name?
    – Jeff Schaller
    Jun 23, 2018 at 12:47
  • It's a hostname. It's the hostname of a proxmox server.
    – masterq
    Jun 23, 2018 at 13:08
  • by using the text sub.mydomain and the phrasing ping my domain, you distract readers. Is your domain externally resolvable? If it's not private data, you could provide the actual domain name; otherwise, more details about your nameserver setup (/etc/resolv.conf) and which DNS servers you think should be able to answer the query.
    – Jeff Schaller
    Jun 23, 2018 at 13:34
  • 1
    dig sub.mydomain.eu. Your machine should not cache dns across boots: The time to live is, usually, to short to make it worth while. Jun 23, 2018 at 14:15
  • Do you have network access? Who is your name server? does dig sub.mydomain.eu @ work? Jun 23, 2018 at 14:20

1 Answer 1


If you use nscd:

nscd -i hosts
  • I installed nscd and that done nothing. Am I supposed to do something after?
    – masterq
    Jun 23, 2018 at 13:07
  • 1
    Maybe it wasn't clear from the wording, but nscd could have interfered with your name resolution if it was running and configured; if you didn't have it installed, installing it is unlikely to help.
    – Jeff Schaller
    Jun 23, 2018 at 13:33

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