In looking at my server logs, I found several PowerDNS (pdns) “Warning!” messages regarding the use of an invalid hint. The warning emphasis is by pdns not mine. This should really be just an informational message and can be ignored.

The Warning message

The following is the warning message that appears in the logs (/var/log/messages by default). If you are using cPanels Zone editor you will see three error messages for the three views it manages.

<Date> <Time> <Server Name> pdns_server: [bindbackend] Warning! Skipping zone '.' because type 'hint' is invalid

What it is telling you.

As of version 2.9.3a of PowerDNS does not use BIND hint zone types per their own documentation (Most recent doc.powerdns.com Changelog History). It also doesn’t use forward zone types. cPanel’s Zone manager creates a generic named.conf file that could be used by either Bind or PowerDNS, so it include the root hints entries.

The offending code

The following is the offending code within the named.conf file

    zone “.” IN {        type hint;        file “/var/named/named.ca”; };

This code is included in three views localhost_resolver, internal and external, each have the above code, and will generate three error messages

What is a root hint

The following is from named.conf documentation.

hint -- The initial set of root-servers is defined using a hint zone. When the server starts up it uses the hints zone file to find a root name server and get the most recent list of root name servers. If no hint zone is specified for class IN, the server uses a compiled-in default set of root servers. Classes other than IN have no built-in default hints.

For more information on root hints, check out the official IANA documentation on Root Files.

A cPanel staff comment

For a more authoritative response to this message. Someone had posted an inquiry on the cPanel forums with a related inquiry. A Tech support manager responded similarly.

The real solution

Instead of ignoring this error message. There are two better solutions to this warning message.

The first is for the maintainers of the cPanel Zone editor to check which DNS software you have selected and create a named.conf file that is specific to that product. They do not need to write a root hints entry for PowerDNS users. This would eliminate this message altogether.

The second solution is for the maintainers of PowerDNS to change this message form a “Warning!” message (emphasis is their’s) to an information message. As anyone running PowerDNS is not expecting to use a root hints anyways.

I will leave it to others in the community to pursue either option. As I don’t have the time. Maybe it will be fixed in a later release of either product.