Configure DNS (BIND) Server on CentOS 7 / RHEL 7

The Domain Name System (DNS) is a hierarchical distributed naming system for computers, services, or any resource connected to the Internet or a private network. It associates various information with domain names assigned to each of the participating entities.

Most importantly, it translates domain names meaningful to humans into the numerical identifiers associated with networking equipment for the purpose of locating and addressing these devices worldwide.

Install BIND package

BIND stands for Berkeley Internet Name Domain, a software which provides an ability to perform name to ip conversion.

# yum -y install bind bind-utils

Configure BIND

Configuration file of bind is /etc/named.conf, open up /etc/named.conf file. Comment out the following line, and this will enable BIND to listen on all ip addresses.

#listen-on port 53 { 127.0.0.1; };
#listen-on-v6 port 53 { ::1; };

Change localhost to any and this will allow clients from the mentioned network can query the DNS for the name to ip translation.

allow-query     { any; };

Create Zones

The following is the forward zone entry in named.conf file, written for the domain.local domain. Edit /etc/named.conf.

zone "domain.local" IN {
        type master;
        file "domain.local";
        };

Create zone files

Now, it’s the time to create a lookup file for a created zone. By default, zone lookup files are placed under /var/named directory. Create a zone file called fwd.domain.local for forward lookup under /var/named directory. All domain names should end with a dot (.).

There are some special keywords for Zone Files

A – A record
NS – Name Server
MX – Mail for Exchange
CNAME – Canonical Name

$TTL 86400
@   IN  SOA     primary.domain.local. root.domain.local. (
2014112511  ;Serial
3600        ;Refresh
1800        ;Retry
604800      ;Expire
86400       ;Minimum TTL
)
;Name Server Information
domain.local.      IN  NS      ns1.domain.local.
;IP address of Name Server
primary IN  A       192.168.12.8
;Mail exchanger
domain.local. IN  MX 10   mail.domain.local.
;A - Record HostName To Ip Address
www     IN  CNAME       domain.local.
mail    IN  A       192.168.12.150
;CNAME record
ftp     IN CNAME        domain.local.

Once zone files are created, restart bind service.

# systemctl restart named.service

Enable it on system startup.

# systemctl enable named.service