Dyndns client (ddclient) for linux

Ddclient is a small piece of software that you install to your computer that updates your dyndns account with your current IP address. If your external IP address changes, this program will automatically notify dyndns.com of the change and update your account information seamlessly.

To install: # apt-get install ddclient

After you install it and provide the relevant information on setup, you will want to verify and or modify the config file (/etc/ddclient.conf)

This is what mines look like

# Configuration file for ddclient
#
# /etc/ddclient.conf

daemon=300 # check every 300 seconds
syslog=yes # log update msgs to syslog
pid=/var/run/ddclient.pid
ssl=yes
protocol=dyndns2
### Select one of these options to determine your IP address
## via hardware interface (if you don't have a router/firewall)

## For local IPs. You probly wouldn' have any use for this unless your computer was connected directly to the modem.
#use=if, if=eth0
## via our CheckIP server. This is a good choice that i use
use=web, web=checkip.dyndns.com/, web-skip='Current IP Address: '

## from the status page for a linksys router/firewall

#use=linksys, fw=linksys, fw-login=admin, fw-p

## settings for DynDNS account holders
################################################################
server=members.dyndns.org
protocol=dyndns2
login=[login]
password=[password]
yourdns.dyndns.org

## settings for OpenDNS account holders
######################################################
#server=updates.opendns.com
#protocol=dyndns2
#login=[login]
#password=[password]
#yourdns.opendns.com

You may also need to verify one setting in the /etc/defaults/ddclient file. You would want to confirm that "run_daemon=true" is set.

After you made all changes, restart the daemon: # /etc/init.d/ddclient restart The service will start on system boot and continue to run in the background.

# /etc/init.d/ddclient status

Status of Dynamic DNS service update utility: ddclient is running

Every few minutes (configurable) the service will check to see if there is a change in your external IP address and if there is, it will send that updated information to your dyndns service provider using your already provided account credentials.

You would then want to log into your dynamic DNS service provider account and verify that your external IP now is up to date.

[update]
I've ran into an issue where one of my ddclients refused to update my dyndns account. I ran it in debug mode like so:
# sudo ddclient -debug -login=username -password='pass' -noquiet -verbose

The ouput of the command was impying that my ip address hasn't changed so it was skipping the update process. However when i log into my dyndns account, my ip address was different. This is because im running the ddclient on a netbook that i take everywhere and when its connected to the internet, it updates that record. The reason that my other machine was not update my dyndns account is becasue of a cache file that was stored. By removing this cache file, it fixed my problem.

# sudo rm /var/cache/ddclient/ddclient.cache