Additional note:

I disabled IPv6 WAN connection.

Now IPv4 WAN is online.

Nevertheless, in Insights - Dynamic DNS, the State is still offline and no updates are sent to Dynamic DNS providers

Hi @MatthiasL22 

Thanks for posting in our business forum.

Who's your DDNS provider? If your provider is a third-party one, have you verified the third-party end is working fine?

If you are using DynDNS, you should use this instead.

Did you bind IPv4 or IPv6?

We don't support dual-stack WAN.

I need the first two parts of your WAN IP. V4 and V6. And this. Mosaic other sensitive information.

  @Clive_A 

Hi,

The Provider is "GoIp" so I chose Custom Provider which was working for several months until now.

The third party end is fine working! If I query the update URL, the DNS entry is updated.

I bound IPv4. First two numbers: 84.144

I mentioned already, that I disabled IPv6 for evaluation.

Hi @MatthiasL22 

Thanks for posting in our business forum.

MatthiasL22 wrote

  @Clive_A 

Hi,

The Provider is "GoIp" so I chose Custom Provider which was working for several months until now.

The third party end is fine working! If I query the update URL, the DNS entry is updated.

I bound IPv4. First two numbers: 84.144

I mentioned already, that I disabled IPv6 for evaluation.

 

If you disabled the IPv6, and does it work correctly to sync with the server?

If it was working before, something must be changed.

  @Clive_A you got it 

That is was I also think!

Even with disabled IPv6 it does not work.

But I just found the solution which is definitely a bug.

I am using WAN/LAN4 as Interface.

WAN/LAN3 was configured as Static IP.

I switched WAN/LAN3 to dynamic IP, which leads to the interface is no longer working, but Dynamic DNS starts working again....

Holy sh....

Hi @MatthiasL22 

Thanks for posting in our business forum.

MatthiasL22 wrote

  @Clive_A you got it 

That is was I also think!

 

Even with disabled IPv6 it does not work.

But I just found the solution which is definitely a bug.

I am using WAN/LAN4 as Interface.

WAN/LAN3 was configured as Static IP.

I switched WAN/LAN3 to dynamic IP, which leads to the interface is no longer working, but Dynamic DNS starts working again....

Holy sh....

If you switch back the WAN/LAN4 as a dynamic IP and does the DDNS work correctly?

Have you tried to reconfig DDNS after it happened?

Or reboot?

Any of the steps above fixes the issue?

Need answers to these questions. Based on that, I'll make my next move.

  @Clive_A 

WAN/LAN4 Interface is and was always using unmodified during Tests: PPPoE!

Setting back WAN/LAN3 to Static IP - dynamic DNS stops working .

Also reboot did not help, reconfig did not help, enable and disable of dynamic dns service did not help.

Setting Back WAN/LAN to Dynamic IP - helped.

Besides that I am wondering if it will possibly to pass not only [IP] but also [IP6] for IPv6?!

Hi @MatthiasL22 

Thanks for posting in our business forum.

MatthiasL22 wrote

  @Clive_A 

WAN/LAN4 Interface is and was always using unmodified during Tests: PPPoE!

 

Setting back WAN/LAN3 to Static IP - dynamic DNS stops working .

Also reboot did not help, reconfig did not help, enable and disable of dynamic dns service did not help.

Setting Back WAN/LAN to Dynamic IP - helped.

 

Besides that I am wondering if it will possibly to pass not only [IP] but also [IP6] for IPv6?!

You are not following me. I am not asking about the WAN/LAN3. You had an issue with the WAN/LAN4, is that correct?

About the WAN/LAN4, as PPPoE, you said it does not work with the DDNS. I am asking about this with my previous questions. So I need answers to that before I escalate it with the running log and backup.

With WAN/LAN4, reboot, re-enable it, and disable IPv6 on WAN, will it work correctly to sync your IPv4 address hourly to the server? Does the Insight show the last update time on an hourly base?

  @Clive_A 

I know that you were not asking about WAN/LAN3 - but changing something there, was influencing the behavior of Dynamic DNS on WAN/LAN4...

That is all I wanted to say.

And Dynamic DNS on WAN/LAN4 is not working if WAN/LAN3 is set to static IP.

In Insights it then only shows "Offline"

Having WAN/LAN3 on dynamic IP, Dynamic DNS for WAN/LAN4 is working, also with enabled IPv6 and also reporting correct in Insights.

I hope I could answer your question.

Hi @MatthiasL22 

Thank you so much for taking the time to post the issue on TP-Link community!

To better assist you, I've created a support ticket via your registered email address, and escalated it to our support engineer to look into the issue. The ticket ID is TKID231045684, please check your email box and ensure the support email is well received. Thanks!

Once the issue is addressed or resolved, welcome to update this topic thread with your solution to help others who may encounter the same issue as you did.

Many thanks for your great cooperation and patience!