CentOS 8 DNS Resolution Not Working As Expected

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[root@localhost ~]# lsb_release -d Description: CentOS Linux release 8.2.2004 (Core)
[root@localhost ~]# cat /etc/resolv.conf
# Generated by NetworkManager search subdomain.company.com company.com nameserver 1.2.3.4
nameserver 5.6.7.8

[root@localhost ~]# host foo foo.subdomain.company.com has address 1.2.3.4

[root@localhost ~]# host foo.subdomain Host foo.subdomain not found: 3(NXDOMAIN)

[root@localhost ~]# host foo.subdomain.company.com foo.subdomain.company.com has address 1.2.3.4
[root@localhost ~]#

The expected result is that the lookup for foo.subdomain works, like it does under CentOS < 8. I tested this also on a RHEL8 machine and followed https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/configuring_and_managing_networking/manually-configuring-the-etc-resolv-conf-file_configuring-and-managing-networking to disable DNS processing by NM, but this did not change the outcome. How can the pre-CentOS 8 behaviour be restored?

5 thoughts on - CentOS 8 DNS Resolution Not Working As Expected

  • man host

    -N ndots
    The number of dots that have to be in name for it to be considered absolute. The default value is that defined using
    the ndots statement in /etc/resolv.conf, or 1 if no ndots statement is present. Names with fewer dots are interpreted
    as relative names and will be searched for in the domains listed in the search or domain directive in
    /etc/resolv.conf.

    P.

  • Pete Biggs writes:

    As per man resolv.conf, the default setting hasn’t changed. It is n=1 on all of CentOS 6/7/8.

  • I also, don’t see a search stanza.

    Best Regards, Strahil Nikolov

    На 6 август 2020 г. 13:30:13 GMT+03:00, isdtor написа:

  • Does

    host -N2 foo.subdomain

    work on CentOS 8? Does it work if you put ndots: 2 in resolv.conf?

    There may have been a change in behaviour – from the tests I’ve done it seems more like it’s fixing a bug/inconsistency somewhere because doing

    host -N1 foo.subdomain

    should not work, but it does on CentOS 7.

    P.