Александр Кириллов писал 2014-09-06 18:32:
There seems to be a problem with my local dns server resolving
mirror.centos.org.
I know something about dns but obviously not enough to figure out
what
might be wrong here or how to fix
this in bind configs. The SERVFAIL errors below seem to be related to
AAAA and MX queries for the domain.
Please advise. TIA.
# host mirror.centos.org 8.8.8.8
Using domain server:
Name: 8.8.8.8
Address: 8.8.8.8#53
Aliases:
mirror.centos.org has address 69.167.139.9
# host mirror.centos.org
mirror.centos.org has address 66.109.26.212
Host mirror.centos.org not found: 2(SERVFAIL)
Host mirror.centos.org not found: 2(SERVFAIL)
# tail -F /var/named/chroot/var/named/data/named.run
error (FORMERR) resolving 'mirror.centos.org/AAAA/IN':
85.12.30.226#53
error (FORMERR) resolving 'mirror.centos.org/AAAA/IN':
93.113.36.66#53
error (FORMERR) resolving 'mirror.centos.org/AAAA/IN':
94.46.190.42#53
error (FORMERR) resolving 'mirror.centos.org/AAAA/IN':
85.12.30.226#53
error (FORMERR) resolving 'mirror.centos.org/AAAA/IN':
93.113.36.66#53
error (FORMERR) resolving 'mirror.centos.org/AAAA/IN':
94.46.190.42#53
error (FORMERR) resolving 'mirror.centos.org/MX/IN': 85.12.30.226#53
error (FORMERR) resolving 'mirror.centos.org/MX/IN': 93.113.36.66#53
error (FORMERR) resolving 'mirror.centos.org/MX/IN': 94.46.190.42#53
error (FORMERR) resolving 'mirror.centos.org/MX/IN': 85.12.30.226#53
error (FORMERR) resolving 'mirror.centos.org/MX/IN': 93.113.36.66#53
error (FORMERR) resolving 'mirror.centos.org/MX/IN': 94.46.190.42#53
Try asking the correct type (A record only) and you'll have the
correct
answer : the three PDNS servers having delegation for
mirror.centos.org
will only answer for A records (we have obviously no MX record for
mirror.centos.org and, unfortunately, no AAAA records for those
machines
either)
PS : host is considered "deprecated" so switch to dig instead ? ;-)
Thanks for your answer, Fabian,
I forgot to mention in the OP that the source of the error is yum with
scl repo enabled:
# yum distro-sync
Loaded plugins: fastestmirror, priorities, refresh-packagekit,
security, verify
...
http://mirror.centos.org/centos/6/SCL/x86_64/repodata/repomd.xml:
[Errno 14] PYCURL ERROR 6 - "Could not resolve host: mirror.centos.org
(Could not contact DNS servers)"
Trying other mirror.
Error: Cannot retrieve repository metadata (repomd.xml) for
repository: scl. Please verify its path and try again
This is an ipv6-enabled system and that's probably why yum tries to get
an ipv6 address first for mirror.centos.org and fails miserably. For
whatever reason I do not get an authoritative negative response for AAAA
query from upstream servers. Well an easy fix is to hardcode an ipv4
address for mirror.centos.org in /etc/hosts and forget it. I suspect
miconfiguration on centos.org side as scl is the only repo which gives
me troubles but don't have the time to dig into this.
_______________________________________________
CentOS mailing list
CentOS@xxxxxxxxxx
http://lists.centos.org/mailman/listinfo/centos
