Nimantha's Blog: How to enable DDNS (Dynamic DNS) in DHCP Clients

1. Configuring the OS to obtain an address from DHCP.

* Edit the “interfaces” file.

root# vi /etc/network/interfaces

* Copy and paste the following in it.

auto eth0

iface eth0 inet dhcp

2. Configuring the OS to register with the DNS

* Edit the “dhclient.conf” file.

root# vi /etc/dhcp/dhclient.conf

* Uncomment the following line by removing the ‘#’. If the line is not present enter it to the file.

# send host-name "hostname";

* Replace the hostname with the real hostname and keep with quotes.

1. Log into the terminal as root and proceed with the following steps.

2. Change the FQDN of the host.

* Enter the FQDN of the host and save the file.

root# vi /etc/nodename

* This command will edit the file nodename file if it exists. If not it will create the file.

3. Configure the OS to update the DNS.

* Enter the following line in the file hostname.network_interface and save.

* Replace the network_interface with the network interface’s name.

inet hostname

* Replace the hostname with the actual hostname.

root# vi /etc/hostname.network_interface

* This command will edit the hostname.network_interface file.

1. Open the configuration file for the network interface.

# vi /etc/sysconfig/network-scripts/ifcfg-eth0

* Here it is done for the interface eth0.

2. Append the following line to it.

DHCP_HOSTNAME=hostname

3. Save and close the file. Restart the network service.

# service network restart

** Please refer to dhclient.conf man page for more information.

$ man dhclient.conf

* Validate whether the ‘Register this connection’s address in DNS is checked.

* Start -> Run -> ncpa.cpl -> right click on the relevant connection -> properties -> double click on TCP/IP -> Advanced -> DNS

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