DNS server setup in Ubuntu 12.04

DNS stands for Domain Name System, which is a hierarchical distributed naming system. It binds an IP address with a name, so that we can use a name for a website/machine rather than remembering its IP address and use IP address, which is very inconvenient. 

In this article we will use Ubuntu 12.04 LTS as our operating system and bind9 for DNS server.

Setup details:

1. IP Address: 172.16.61.130
2. Domain name: alokranjan.net

Note: Your system's IP may be different and domain name can be of your choice.

Lets start with the installation of bind9 package, which can be installed as below:

alok@ranjan:~$ sudo apt-get install bind9 -y

Once the bind9 package will be installed successfully. we can go ahead with the configuration of a basic DNS server.

First of all, we will edit "/etc/bind/named.conf.local". In this file we define forward zones and reverse zones. That means, when we enter domain name it will translate/resolve into its corresponding IP address and when we use an IP address it will translate/resolve it into name." 

Modified named.conf.local file as following:

zone "alokranjan.net" {
        type master;
        file "/etc/bind/db.alokranjan";
};

zone "61.16.172.in-addr.arpa" {
        type master;
        file "/etc/bind/db.172"; 
};

Where 61.16.172 came from my IP address (172.16.61.130) by eliminating last octet and reversing it.

Now we need to create db.alokranjan and db.172 in /etc/bind/ directory.

/etc/bind/db.alokranjan:

Fig 1:/etc/bind/db.alokranjan

/etc/bind/db.172:

Fig 2:/etc/bind/db.172

Congratulations, we have successfully configured our DNS server. Now we will restart our bind9 service as below:

sudo /etc/init.d/bind9 restart

Now, we need to configure our system (client) to use this DNS server. For this purpose we will edit /etc/resolv.conf as below:

nameserver 172.16.61.130

Now if we use nslookup (nslookup alokranjan.net) to check the IP for alokranjan.net it will show the IP 172.16.61.130.

Bazinga... It's done.