Common Mistakes to Avoid

It is very common for beginners to make mistakes when editing BIND configuration files or run in to initial difficulties using named. Be sure to avoid the following problems:

• Make sure you increment the serial number when editing a zone file.

  If the serial number is not incremented, your master nameserver may have the correct, new information, but your slave nameservers will never be notified of the change or attempt to refresh their data of that zone.

• Be careful to use ellipses and semi-colons correctly in the /etc/named.conf file.

  An omitted semi-colon or unclosed ellipse section will cause named to refuse to start.

• Remember to place dots (.) in zone files after all FQDNs and omit them on hostnames.

  The dot denotes a fully qualified domain name. If the dot is omitted, then named will place the name of the zone or the $ORIGIN value after the name to complete it.

• If you are having problems with your firewall blocking connections from your named program to other nameservers, you may need to edit its configuration file.

  By default, BIND version 9 uses random ports above 1024 to query other nameservers. Some firewalls, however, expect all nameservers to communicate using only port 53. You can force this behavior by adding the following line to an options statement in /etc/named.conf:

  query-source address * port 53;