Caching Name Server for CentOS 6.x

Step 1: Install the BIND Packages using Yum

Install bind packages using below command. In CentOS the caching-nameserver package has been included with bind package.

# yum install bind bind-chroot

Step 2: Copy default bind configuration File

Copy bind configuration file from bind sample files using below command. Change the path of files as per version you have installed.

cd /var/named/chroot/etc
cp /usr/share/doc/bind-9.9.2/sample/etc/named.conf  .
cp /usr/share/doc/bind-9.9.2/sample/etc/named.rfc1912.zones  .

Step 3: Make changes in Configuration File

Edit bind configuration file in your favorite editor and make necessory changes as per below settings or use below configuration.

// /var/named/chroot/etc/named.conf
options {
        listen-on port 53 { 127.0.0.1; any; };
        listen-on-v6 port 53 { ::1; };
        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";
        allow-query     { localhost; any; };
        allow-query-cache    { localhost; any; };
        recursion yes;

        dnssec-enable yes;
        dnssec-validation yes;
        dnssec-lookaside auto;

        /* Path to ISC DLV key */        bindkeys-file "/etc/named.iscdlv.key";

        managed-keys-directory "/var/named/dynamic";
};

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

include "/etc/named.rfc1912.zones";

Update permissions on configuration files.

# chown root:named named.conf named.rfc1912.zones

Step 4: Check Configuration File

We recommend to check dns configuration file before restarting service.

# named-checkconf named.conf

Step 5: Restart Bind Service

Start Bind (named) service using below command.

# service named restart

Enable auto start bind service on system boot.

# chkconfig named on

Step 6: Finally test Caching Only DNS Setup

Send query to your dns server directly using below command.
Syntax: nslookup < domainname > < caching dns server name/ip >

# nslookup Hostripples.com 192.168.1.1

Sample Output:

Server:         192.168.1.1
Address:        192.168.1.1#53

Non-authoritative answer:
Name:   hostripples.com
Address: 198.27.89.220
Name:   hostripples.com
Address: 198.27.89.220