Bind9 slave not updating
If you intend to serve a registered domain name they ensure that your DNS zone is still available even if your primary server is not online.
You can even configure BIND9 to be a Caching and Primary Master DNS server simultaneously, a Caching and a Secondary Master server or even a Caching, Primary Master and Secondary Master server.
Chroot BIND9 Guide reference: to the /etc/init.d/bind9 file a chrooted environment should be running in /var/lib/named and not /chroot/named as this howto is showing.
Please feel free to change it, if you find the need to do so.
Note: There are some issues with this Howto, too numerable to fix quickly, and it requires bringing up to standard. in all other places, the document uses the machine name example ns.
Also, you need set use-alt-transfer-source to yes so that the alternate transfer sources can be used.
I modified the example file to give box an address of 192.168.1.21).
Domain Name Service (DNS) is an Internet service that maps IP addresses and fully qualified domain names (FQDN) to one another.
This setup works as well without any issues I have occoured.
The installation is very simple, like almost all debian applications.