Best way to get DDNS for DtDNS.com on RN104

Well that wasn't simple but finally got it working and thought I'd post how to help others...

I did try the DDClient that comes with the NAS apps, but it gets complicated.  As per this post (https://community.netgear.com/t5/Using-your-ReadyNAS/ddclient-seting-up-readynas-104-missing-ddclient-conf-file/m-p/1019730#M100107), the install recommends editing the ddclient.conf file in the DDClient share.  This issue is this is a link to a file retained in the /etc folder.  Although the ddclient link in the NAS share has all file permissions enabled, it doesn't help, as the 'real' file in the /etc folder has only -rw------, which means you have to Putty into the NAS under SSH and logged in as root to be able to edit it!

This effecetively means enabling SSH and for password authentication and enabling shell access for admin (I think) - at least that was the only way I managed it - which means you have to remember to close it all down again after you're done.

So once you have opened the terminal window and logged in as 'root' using your admin user password, navigate to /etc using 'cd /etc' and just check you can see the ddclient.conf file using 'ls -la'.

Now you have to learn the linux editor 'vi' to be able to edit the ddclient.conf file in the Putty terminal window.  Lots of You Tube video tutorials, but its a real pain initially as all of your normal ways of editing in Windows are useless.  Basically learn how to put 'vi' editor into command and edit mode and learn the necessary shortcuts to exit, save, delete lines etc.

There is a good list of different configs for different DDNS providers here (https://sourceforge.net/p/ddclient/git/ci/60fe051b7a504573386e2df2ffa8703dd47a8cb9/tree/sample-etc_ddclient.conf) and mine almost worked first time, except it didn't.  Using the config directions from this page I swapped all of the config in the ddclient.conf file for:

protocol=dtdns
server=www.dtdns.com
client=ddclient
password=mypassword

mydomainwithdtns.com

NB note the fact you don't need your username!

Eventually I tried a few things and finally after adding 'use=web' to tell the ddclient where to get the IP address from to upload to DtDNS, it seems to work - yay!!

So my ddclient.conf file now reads:

use=web

protocol=dtdns
server=www.dtdns.com
client=ddclient
password=mypassword

mydomainwithdtns.com

Save, exit vi editor, close putty, restart DDClient app in the NAS and you should be done!  If you find this difficult to follow, then don't bother, as I have written it for a newbie linux user like myself to follow... any less proficient and you probably risk leaving your NAS open or vunerable.  Obviously those with more knowledge will find this overly simple, but hopefully will help anyway.