How to Update ROOT Hints DNS ?

My WebServer DNS root zone file is outdated and it has no information about IPv6 and recently changed root server IP address. How do I update my root hints data file under CentOS 7 Server?

Under Red Hat / CentOS / Fedora Linux, default location is /var/named/named.root, enter:

 # wget --user=ftp --password=ftp ftp://ftp.rs.internic.net/domain/db.cache -O /var/named/named.root 

Reload rndc to update information, enter:

 # rndc reload 

Another option is run dig command to fetch information:

 # dig +bufsize=1200 +norec NS . @a.root-servers.net > /var/named/named.root 

The root zone's nameservers change over time, don't assume this list is current. Always download a new version of db.cache once or twice year is sufficient.

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