I was having trouble with a Tenvis IP camera model JPT3815W updating it’s built in DDNS.
For the record my original DDNS that is on the sticker must have expired. I was doing everything right as it was working fine and then all of a sudden one day it fails to update my IP.
If any one else has a similar problem just ask for a new DDNS user and pass and change it. First to make sure go to google and type “my ip” then take that number and add your port to the end using xx.xx.xx.xx:2222 (2222 is an example) Click enter and it should resolve to the camera asking for your user pass to log into the camera. If this works you know you have your port forwarding correct. It is the built in DDNS that is expired or failing at Tenvis.
Ask a Mod at the Tenvis support forum for a new user and pass and be done with it. They will provide a Word Doc with specific instructions. When I first made the changes to the camera they didn’t stick. I then went back and clicked ok after every change I made until all was set. I think you need to be kinda quick when making the changes. I then had to log into the camera and click save twice before I saw that the DDNS updated successfully. Make sure to make a new sticker on the camera so you remember the new DDNS info, and also to avoid confusion in the future.