Plesk DNS doesn’t work for some domains: checkhints: b.root-servers.net/A (203.0.113.2) missing from hints

Symptoms

• Plesk Obsidian running on a Linux-based operating system

• The Plesk DNS server doesn't answer DNS queries for some domains that are hosted on the Plesk server:

  dig a +short example.com @203.0.113.2
  (empty output)

• The following errors can be found in the BIND / named service

  # systemctl status named.service
  [...]
  Jan 01 00:00:00 example.com named[1234567]: checkhints: b.root-servers.net/A (203.0.113.3) missing from hints
  Jan 01 00:00:00 example.com named[1234567]: checkhints: b.root-servers.net/A (203.0.113.4) extra record in hints
  Jan 01 00:00:00 example.com named[1234567]: checkhints: d.root-servers.net/A (203.0.113.5) missing from hints
  Jan 01 00:00:00 example.com named[1234567]: checkhints: d.root-servers.net/A (203.0.113.6) extra record in hints
  Jan 01 00:00:00 example.com named[1234567]: checkhints: h.root-servers.net/A (203.0.113.7) missing from hints
  Jan 01 00:00:00 example.com named[1234567]: checkhints: h.root-servers.net/A (203.0.113.8) extra record in hints
  Jan 01 00:00:00 example.com named[1234567]: checkhints: j.root-servers.net/A (203.0.113.9) missing from hints
  Jan 01 00:00:00 example.com named[1234567]: checkhints: j.root-servers.net/A (203.0.113.10) extra record in hints
  Jan 01 00:00:00 example.com named[1234567]: checkhints: l.root-servers.net/A (203.0.113.11) missing from hints
  Jan 01 00:00:00 example.com named[1234567]: checkhints: l.root-servers.net/A (203.0.113.12) extra record in hints

• The last named.root root nameservers update was a very long time ago

  # grep update /var/named/run-root/var/named.root
  ; last update: Aug 22, 1997

  # grep update /var/named/chroot/var/named.root
  ; last update: Aug 22, 1997

Cause

Severely outdated root nameservers. The named.root is a text file that contains names and IP addresses of the internet's root domain servers and should be kept up to date.

Resolution

1. Connect to the server via SSH

2. Update the named.root file by executing the following command:

   Ubuntu/Debian-based

   # wget -O /var/named/run-root/var/named.root https://www.internic.net/domain/named.root

   RHEL-based

   # wget -O /var/named/chroot/var/named.root https://www.internic.net/domain/named.root

3. Restart the BIND DNS service in the Plesk server by executing the following command:

   # service named-chroot restart