The DNS configuration files are stored in the /etc/bind directory. The primary configuration file is /etc/bind/named.conf.

The include line specifies the filename which contains the DNS options. The directory line in the /etc/bind/named.conf.options file tells DNS where to look for files. All files BIND uses will be relative to this directory.

The file named /etc/bind/db.root describes the root nameservers in the world. The servers change over time, so the /etc/bind/db.root file must be maintained now and then. This is usually done as updates to the bind9 package. The zone section defines a master server, and it is stored in a file mentioned in the file option.

It is possible to configure the same server to be a caching name server, primary master, and secondary master. A server can be the Start of Authority (SOA) for one zone, while providing secondary service for another zone. All the while providing caching services for hosts on the local LAN.

The default configuration is setup to act as a caching server. All that is required is simply adding the IP Addresses of your ISP's DNS servers. Simply uncomment and edit the following in /etc/bind/named.conf.options:

forwarders {
                1.2.3.4;
                5.6.7.8;
           };

Now restart the DNS server, to enable the new configuration. From a terminal prompt:

sudo service bind9 restart

See dig for information on testing a caching DNS server.

In this section BIND9 will be configured as the Primary Master for the domain example.com. Simply replace example.com with your FQDN (Fully Qualified Domain Name).

Once a Primary Master has been configured a Secondary Master is needed in order to maintain the availability of the domain should the Primary become unavailable.

First, on the Primary Master server, the zone transfer needs to be allowed. Add the allow-transfer option to the example Forward and Reverse zone definitions in /etc/bind/named.conf.local:

zone "example.com" {
        type master;
	file "/etc/bind/db.example.com";
        allow-transfer { 192.168.1.11; };
};

zone "1.168.192.in-addr.arpa" {
        type master;
        file "/etc/bind/db.192";
	allow-transfer { 192.168.1.11; };
};

Restart BIND9 on the Primary Master:

sudo service bind9 restart

Next, on the Secondary Master, install the bind9 package the same way as on the Primary. Then edit the /etc/bind/named.conf.local and add the following declarations for the Forward and Reverse zones:

zone "example.com" {
	type slave;
        file "db.example.com";
        masters { 192.168.1.10; };
};        
      
zone "1.168.192.in-addr.arpa" {
	type slave;
        file "db.192";
        masters { 192.168.1.10; };
};

Restart BIND9 on the Secondary Master:

sudo service bind9 restart

In /var/log/syslog you should see something similar to (some lines have been split to fit the format of this document):

client 192.168.1.10#39448: received notify for zone '1.168.192.in-addr.arpa'
zone 1.168.192.in-addr.arpa/IN: Transfer started.
transfer of '100.18.172.in-addr.arpa/IN' from 192.168.1.10#53:
 connected using 192.168.1.11#37531
zone 1.168.192.in-addr.arpa/IN: transferred serial 5
transfer of '100.18.172.in-addr.arpa/IN' from 192.168.1.10#53:
 Transfer completed: 1 messages, 
6 records, 212 bytes, 0.002 secs (106000 bytes/sec)
zone 1.168.192.in-addr.arpa/IN: sending notifies (serial 5)

client 192.168.1.10#20329: received notify for zone 'example.com'
zone example.com/IN: Transfer started.
transfer of 'example.com/IN' from 192.168.1.10#53: connected using 192.168.1.11#38577
zone example.com/IN: transferred serial 5
transfer of 'example.com/IN' from 192.168.1.10#53: Transfer completed: 1 messages, 
8 records, 225 bytes, 0.002 secs (112500 bytes/sec)

zone "example.com" {
	type master;
	file "/etc/bind/db.example.com";
	allow-transfer { 192.168.1.11; };
	also-notify { 192.168.1.11; }; 
	};

zone "1.168.192.in-addr.arpa" {
	type master;
	file "/etc/bind/db.192";
	allow-transfer { 192.168.1.11; };
	also-notify { 192.168.1.11; }; 
	};