Centos / RHEL-6.X Chacheng Oo Sr. System Engineer (IT) DBL Group|BGMEA Complex( 12th Floor )| 23/1 Panthapath Link Road | Karwan Bazar | Dhaka-1215 | Bangladesh| Tel:+88-02-8140207-12 |Fax: +88-02-8140214 | Cell: +88-01755647625 Or 01812-490773 | Skype ID : Chacheng.oo |E-mail: chacheng@dbl-group.com , chacheng.oo@gmail.com | www.dbl-group.com |

1. Application: Name Resulation
Name => IP (www.dbl-group.com => 203.112.194.17)IP
=> Name (203.112.194.17 => www.dbl-group.com)
Daemon: named
Packages: bind
Port: 53
Protocol: TCP and UdP
Configuration file:
=> /etc/sysconfig/network-scripts/ifcfg-en*
=> /etc/hosts
=> /etc/hostname
=> /etc/named.conf
=> /etc/named.rfc1912.zones
=> /var/named/named.localhost (Forward Zone)
=> /var/named/named.looback (Reverse Zone)
Step 01: Set Static IP Address and DNS:
--------------------------------------
[root@desktopX ~]# cd /etc/sysconfig/network-scripts/
[root@desktopX network-scripts]# ls
[root@desktopX network-scripts]# vim ifcfg-en* ; your Interface name
NAME=********
HWADDR=*******
TYPE=Ethernet
BOOTPROTO=none
IPADDR=192.168.11.X
NETMASK=255.255.255.0
GATEWAY=192.168.11.1
ONBOOT=yes
DNS1=192.168.11.X
[root@desktopX network-scripts]# systemctl stop NetworkManager.service
[root@desktopX network-scripts]# systemctl disable NetworkManager.service
[root@desktopX network-scripts]# systemctl restart network.service
[root@desktopX network-scripts]# cat /etc/resolv.conf
Step 02: Local resolver entry:
------------------------------
[root@desktopX ~]# vim /etc/hosts
192.168.11.X ns1.example.com ns1 ; add below of 2 lines
* save and exit
[root@desktopX ~]# ping ns1.example.com
Step 03: Set Static Host Name and Reboot:
----------------------------------------
[root@desktopX ~]# vim /etc/hostname
ns1.example.com
[root@desktopX ~]# reboot
Step 04: Install Required RPM:

2. ------------------------------
[root@ns1 ~]# yum install bind* -y
Step 05: Allow DNS Server IP and Network:
----------------------------------------
[root@ns1 ~]# cp /etc/named.conf /etc/named.conf.backup
[root@ns1 ~]# vim /etc/named.conf
11 listen-on port 53 { 127.0.0.1; 192.168.11.X; };
12 # listen-on-v6 port 53 { ::1; };
17 allow-query { localhost; 192.168.11.0/24; };
Step 06: Set Forward and Reverse Zones:
---------------------------------------
[root@ns1 ~]# cp /etc/named.rfc1912.zones /etc/named.rfc1912.zones.backup
[root@ns1 ~]# vim /etc/named.rfc1912.zones
19 zone "example.com" IN {
20 type master;
21 file "example.com.for";
22 allow-update { none; };
23 };
31 zone "11.168.192.in-addr.arpa" IN {
32 type master;
33 file "example.com.rev";
34 allow-update { none; };
35 };
Step 07: Create Forward and Reverse Zone Files:
-----------------------------------------------
[root@ns1 Desktop]# cd /var/named/
[root@ns1 named]# ls
[root@ns1 named]# cp named.localhost example.com.for
[root@ns1 named]# cp named.loopback example.com.rev
[root@ns1 named]# ls -l
Step 08: Set Ownership to Forward and Reverse Zone Files:
---------------------------------------------------------
[root@ns1 named]# ll example.com.*
-rw-r-----. 1 root root 152 Mar 21 13:59 example.com.for
-rw-r-----. 1 root root 168 Mar 21 13:59 example.com.rev
[root@ns1 named]# chgrp named example.com.*
[root@ns1 named]# ll example.com.*
-rw-r-----. 1 root named 152 Mar 21 13:59 example.com.for
-rw-r-----. 1 root named 168 Mar 21 13:59 example.com.rev
Step 09: Edit Forward Zone File:
--------------------------------
[root@ns1 named]# vim example.com.for
$TTL 1D
@ IN SOA ns1.example.com. root.example.com. (
0 ; serial
1D ; refresh
1H ; retry

3. 1W ; expire
3H ) ; minimum
IN NS ns1.example.com.
IN A 192.168.11.X
ns1 IN A 192.168.11.X
Note:
-----
SOA - Start of Authority
IN - Internet
NS - Name Server (DNS Server)
A - Host Record (IP Address)
root - email admin
PTR - Pointer (Reverse)
Step 10: Edit Reverse Zone File:
--------------------------------
[root@ns1 named]# vim example.com.rev
$TTL 1D
@ IN SOA ns1.example.com. root.example.com. (
0 ; serial
1D ; refresh
1H ; retry
1W ; expire
3H ) ; minimum
IN NS ns1.example.com.
X IN PTR ns1.example.com.
Step 11: Service restart and configured active at boot time:
------------------------------------------------------------
[root@ns1 named]# systemctl restart named.service
[root@ns1 named]# systemctl enable named.service
Step 12: Checking DNS
---------------------
[root@ns1 named]# nslookup ns1.example.com
Server: 192.168.11.X
Address: 192.168.11.X#53
Name: ns1.example.com
Address: 192.168.11.X
[root@ns1 named]# dig -x 192.168.11.X ; here -X is option
status: NOERROR
[root@ns1 named]# dig ns1.example.com
status: NOERROR
[root@ns1 named]# ping www.google.com
======================= Thank you ======================