DNS Server Configuration

INTRODUCTION TO DNS SERVER

DNS provides the resolution of host names to IP &

vice versa. . e.g www.wbut.ac.in to 192.168.43.10 (IPv4)

Defines a hierarchical name space where each level of the namespace is separated by a “ . ”

e.g 192.168.64.27(class B).

Types of DNS Server

Master DNS server:-Stores authorative records for your domain

Slave DNS server:-Relies on master DNS server for data.

Caching-only DNS server:-Stores recent requests like a proxy server.

Forwarding –only DNS server:-Refers to all requests to other DNS servers.

DNS Master server configuration

STEP-1:

bind & caching name server .

rpm is required to configure DNS. Check them for install ,if not installed, install them as

[root@server~]# rpm –qa cach*

[root@server~]# rpm –qa bind*

DNS Master server configurationSTEP-2: Set hostname to

server.example.com .

[root@server~]# cat/etc/

sysconfig /network

HOSTNAME= server.example.com

Set IP address to 192.168.0.254

[root@server~] ifconfig etho

inet addr: 192.168.0.254

STEP-3: Create the main configuration file

for DNS, that is named.conf.• By default a sample file/var/named/chroot/etc/named.

caching- nameserver .conf ,is created

Edit this one by named.conf file or create new one as

[root@server etc]# vi/ var/named/chroot/etc/named.conf

Set directory location for

Forward zone and Reverse lookup zone

DNS Master server configuration

DNS Master server configuration STEP-4:Configure example.com.zone for forward zone and 0.168.192.in-

address.arpa for reverse zone. They will be stored in “/var/named/chroot/var/named/” location.

Change directory to

[root@server named]# cd/ var/named/chroot/var/namedCopy sample file to name we have set in named.conf.

[root@server named]# cp localhost.zone example.com.zone

[root@server named]# cp named.local 0.168.192.in-addr.arpa.zone

DNS Master server configuration

STEP-5:Open forward zone

file [root@server

named]# vi example.com.zone

and modify as

DNS Master server configuration

STEP-5 contd:

Open reverse lookup zone file

[root@server named]# vi 0.168.192.in-addr.arpa.zone

and modify as

DNS Master server configuration

STEP-6:Change the ownership of these zone file to named group.

[root@server named]# chgrp named example.com.zone

[root@server named]# chgrp named 0.168.192.in-addr.arpa.zone

DNS Master server configuration STEP-7:Now start the named service

If service restart without any error then the master name server is successfully configured

DNS is an integral part in most protocols used in the internet.

Makes the internet human friendly for all of us..

Is the world’s largest distributed database system.

Fits the international model perfectly. In simple terms DNS is a mapping

between names and IP addresses.

Summary