Update Root Hints Bind 9
The root hint file is used by your bind server to lookup domains it doesn’t have cached. Every so often the root server IPs change, so keeping this file updated is a good idea.
Here’s a quick and dirty way you can update your bind 9 root hints via a cron job. You can schedule it to run every 6 months or so.
Your root hings file may be either named.ca or named.root. Do a quick search and locate where the file lives on your server and update everything accordingly.
This will download a new version, then restart DNS services.
wget ftp://ftp.rs.internic.net/domain/db.cache -O /var/named/named.ca && rndc reload