Setup a Basic Recursive Caching DNS Server and Configure Zones for Domain

Installing and Configuring a DNS Server

In Linux, the most used DNS server is bind (short for Berkeley Internet Name Daemon), which can be installed as follows:

# yum install bind bind-utils        [CentOS]
# zypper install bind bind-utils     [openSUSE]
# aptitude install bind9 bind9utils  [Ubuntu]

Once we have installed bind and related utilities, let’s make a copy of the configuration file before making any changes:

# cp /etc/named.conf /etc/named.conf.orig            [CentOS and openSUSE]
# cp /etc/bind/named.conf /etc/bind/named.conf.orig  [Ubuntu]

Then let’s open named.conf and head over to the options block, where we need to set make sure the following settings are present to configure a recursive, caching server with IP 192.168.0.18/24 that can be accessed only by hosts in the same network (as a security measure).

The forwarders settings are used to indicate which name servers should be queried first (in the following example we use Google’s name servers) for hosts outside our domain:

options {
...
listen-on port 53 { 127.0.0.1; 192.168.0.18};
allow-query 	{ localhost; 192.168.0.0/24; };
recursion yes;
forwarders {
    	8.8.8.8;
    	8.8.4.4;
};
…
}

Outside the options block, we will define our sales.me.com zone (in Ubuntu this is usually done in a separate file called named.conf.local) that maps a domain with a given IP address and a reverse zone to map the IP address to the corresponding domain.

However, the actual configuration of each zone will go in separate files as indicated by the file directive (“master” indicates we will only use one DNS server).

Add the following blocks to named.conf file:

zone "sales.me.com." IN {
    type master;
    file "/var/named/sales.me.com.zone";
};
zone "0.168.192.in-addr.arpa" IN {
    type master;
    file "/var/named/0.162.192.in-addr.arpa.zone";
};

Note that in-addr.arpa (for IPv4 addresses) and ip6.arpa (for IPv6) are conventions for reverse zone configurations.

After saving the above changes to named.conf, we can check for errors as follows:

# named-checkconf /etc/named.conf

If any errors are found, the above command will output an informative message with the cause and the line where they are located. Otherwise, it will not return anything.