Tutorials Linux DDNS Update Client INADYN

The Dynamic DNS client INADYN is well used around the world. It is typically found on OpenWRT, DD-WRT Routers, and now can be on your Palm Pre. The INADYN service maintain your IP address in relation to the DNS hosting of your choice. This should help friends reach services you may run in the future. Services such as Dropbear, lighttpd and SFTP. It's assumed that firewall configuration on WiFi connections will need attention.

Authentication through DNS matching can now be achieved.

Configuration details for DDNS services listed below:
 * dyndns
 * easydns
 * afraid
 * no-ip
 * tzo
 * zoneedit
 * changeip
 * regfish
 * dnsomatic

Below are simple get-to syntax & conf examples.

Installing inadyn backend service
/opt/bin/ipkg-opt update /opt/bin/ipkg-opt install inadyn

Configuration of inadyn service
The available options of inadyn are documented on the website in the readme. All options can be given via the commandline (directly in the upstart script, or via a dedicated configuration file.) The following is a sample configuration for inadyn to update a host under a freedns.afraid.org account. Adapt this for your dns service. /var/opt/etc/inadyn.conf dyndns_system default@freedns.afraid.org alias palmpre.evilvho.st dyndns_server_name freedns.afraid.org dyndns_server_url /dynamic/update.php?**** update_period_sec 400 verbose 0 The following is a sample call of inadyn on the commandline, providing options for No-IP.com: inadyn --dyndns_system default@no-ip.com -u  -p  -a  Note WiFi (eth0) may/will override Evdo (ppp0) DNS settings with the above code. Services on <1024 may/will be firewalled. However if UPnP is enabled we can utilize //libupnp// (The Universal Plug and Play (UPnP) SDK for Linux provides support for building UPnP-compliant control points, devices, and bridges)

Running inadyn
See Tutorials_Linux_DDNS_Update_Client_wget if your dynamic DNS supports URL based updates (i.e. freedns.afraid.org) to ensure updates are always with your device's radio IP. This method also doesn't require an always-on daemon, and updates only when your IP changes.

Alternative 1: run inadyn in the background upon system start
The following is a sample upstart script to run inadyn on system start: /etc/event.d/webos-inadyn description "inadyn Daemon for WebOS" author "oc80z" start on started nice 5 respawn exec /opt/bin/inadyn --input_file /var/opt/etc/inadyn.conf

Alternative 2: run inadyn when your ppp0 (3G) IP changes
If you want to only run updates with inadyn when 3G (EVDO, UMTS ..) connects, you can use the --iterations option, and set it up like the previous method which will keep the memory free when it's not updating. If you do this, make sure to turn off the auto start described above in Alternative 1 by removing /etc/event.d/webos-inadyn.

Add a script to /etc/ppp/ip-up.d called 09update-ddns. Here are the contents of that /etc/ppp/ip-up.d/09update-ddns: /opt/bin/inadyn --input_file /var/opt/etc/inadyn.conf --iterations 1 > /dev/null 2>&1 || /bin/true
 * 1) !/bin/sh

Make this script executable: chmod 755 /etc/ppp/ip-up.d/09update-ddns