Configuring and Deploying DNS servers (primary, secondary, root and cache on centos 6.5) - Part 2 - Secondary DNS

This walk-through assumes that you have initial deployment of Primary DNS server. Look at my previous post for that.

Configuration on Primary DNS server:

• edit /etc/named.conf

add the allow transfer statement in your zone declaration(both forward and reverse)

 zone "msm.net" {
        type master;
        file "msm.net.db";
        allow-transfer { 192.168.12.3; };
};

zone "12.168.192.in-addr.arpa" {
        type master;
        file "msm.net.rev.db";
        allow-transfer { 192.168.12.3; };
};

•  Allow firewall to communicate on tcp/udp port 53
• iptables -I INPUT -p tcp --dport 53 -j ACCEPT
• iptables -I INPUT -p udp --dport 53 -j ACCEPT

• Restart the named deamon
• service named restart

Configuration on Secondary DNS server:

Make sure you have internet access.

• Install Bind packages
• yum install bind bind-utils bind-chroot bind-libs

• edit /etc/named.conf

 listen-on port 53 { 192.168.12.3; }; //Ip address of the machine
*Remove the allow-query line
*Optional: remove recursion statement and the "." zone to disable recursion and caching.

 zone "msm.net" { //your forward zone statement, same as primary
        type slave; //slave sets this server as slave
        file "msm.net.db"; //the file name that you created in primary
        masters { 192.168.12.2; }; //this is telling the server that this ip is my primary dns's ip
        allow-transfer { none; };
};

zone "12.168.192.in-addr.arpa" { //reverse lookup zone statement, same as primary
        type slave; //this sets this server as a slave of this reverse zone
        file "msm.net.rev.db";  //the file name that you created in primary for reverse  zone
        masters { 192.168.12.2; }; //primary server's ip address
        allow-transfer { none; };
};

• Add exception in SELINUX
•  setsebool -P named_write_master_zones 1

• make name the owner of /var/named directory
• chown named:named /var/named

• Start the named daemon
• service named start

• Check logs if everything went well. It should say zone loaded and file transfered
• tail -30 /var/log/messages

 named[21296]: transfer of 'msm.net/IN' from 192.168.12.2#53: Transfer completed: 1 messages, 7 records, 206 bytes, 0.001 secs (206000 bytes/sec)


If everything went fine then you should see your zone files under /var/named automatically transferred by starting the named daemon, this transfer of file is called a zone transfer.

Prefer a video walk-through? have a look...