DOMAIN NAME SYSTEM (DNS)

DNS is very important component of network infrastructure, without DNS we can’t browse a website with host-name. DNS translate human readable hostnames such as www.chaulv8x.com into machine readable ip addresses such as 128.199.241.169

This translation also occurs when you are connecting to other system on your local network through their host-names instead of their IP addresses. Most of Internet DNS Server (root DNS Servers) run BIND as their DNS software.

Server Name = dns.chaulv8x.com

Server IP       = 192.168.0.211/24

Step 1. Installation of required packages.

We will use yum to install BIND packages.

# yum -y install bind bind-libs bind-utils

Step 2.  Set BIND service start on system boot

# chkconfig –-level 35 named on

Step 3. Start named service for generating some default configuration files.

# service named start

Step 4. Edit main configuration file and add zone entry of www.chaulv8x.com

# vi /etc/named.conf
//// named.conf//// Provided by Red Hat bind package to configure the ISC BIND named(8) DNS// server as a caching only nameserver (as a localhost DNS resolver only).//// See /usr/share/doc/bind*/sample/ for example named configuration files.//

options {
        directory       "/var/named";dump-file       "/var/named/data/cache_dump.db";
        statistics-file "/var/named/data/named_stats.txt";
        memstatistics-file "/var/named/data/named_mem_stats.txt";
        recursion yes;

        dnssec-enable yes;
        dnssec-validation yes;
        dnssec-lookaside auto;/* Path to ISC DLV key */
        bindkeys-file "/etc/named.iscdlv.key";};

logging {
        channel default_debug {
                file "data/named.run";
                severity dynamic;};};

zone "." IN {
        type hint;
        file "named.ca";};
zone "chaulv8x.com"{
        type master;
        file "chaulv8x.com.fwd";};
zone "0.168.192.in-addr.arpa"{
        type master;
        file "chaulv8x.com.rev";};
include "/etc/named.rfc1912.zones";

Step 5. Create Zone files which we mentioned in named.conf file.

# cd /var/named
# vi chaulv8x.com.fwd
$ORIGIN chaulv8x.com.

$TTL 3D
@       SOA     dns.chaulv8x.com.     root.chaulv8x.com.(12 4h 1h 1w 1h)
@       IN      NS      dns.chaulv8x.com.
dns.chaulv8x.com.     IN      A       192.168.0.211
www                                     IN      A       192.168.0.211
# vi chaulv8x.com.rev
$ORIGIN 0.168.192.in-addr.arpa.

$TTL 3D
@       SOA     dns.chaulv8x.com.     root.chaulv8x.com.(12 4h 1h 1w 1h)
@       IN      NS      dns.chaulv8x.com.211     IN      PTR     dns.chaulv8x.com.

Step 6.  Restart BIND Service

# service named restart

Step 7.  Test your DNS server

Note : Before testing , make sure your /etc/resolve.conf file contain DNS server ip that has been set up.

# cat /etc/resolve.conf

search chaulv8x.com

nameserver 192.168.0.211
# nslookup www.chaulv8x.com
Server:         192.168.0.211
Address:        192.168.0.211#53
Name:   www.chaulv8x.com
Address:192.168.0.211
# nslookup 192.168.0.211
Server:         192.168.0.211
Address:        192.168.0.211#53
211.0.168.192.in-addr.arpa      name = dns.chaulv8x.com.