@SergioPichu 

Hi, thanks for posting question here.

I afraid that it is normal. It is suggested to read the Note part in the DDNS guide to know more.

  @Marvin_S 

Sorry, but I don't know if I understand correctly.

Are you saying that the configuration cannot be restored on another computer?

I have previous experience with DDNS and openvpn and I had also already read the links you mentioned.

I have already configured one  router, and it is working fine.  I can connect through the VPN fine.

But I want to have the other one configured in the same way, in case the first one fails. I already backed up and restored the second one. The network settings work fine, but it doesn't restore the DDNS settings.

I don't see the DDNS domain login with the tplink id.

  @SergioPichu 

Hi, thanks for your detailed update.

The backup feature is only to back up local information from the first router, not from Cloud. If you select TP-LINK as the DDNS service provider, it is related to the the cloud. So the DDNS does not work on your second router. If you use a third-party DDNS server provider, which should be ok.

  @Marvin_S  thanks a lot.

you have been very clear.  But would you be so kind as to answer me one more question?

So I can assume that the VPN settings are also restored?    (I mean the server certificate)

And one last question: if I reserve a new domain for the second router in tplinkdns and it doesn't have access for a long time (because that device remains offline) is it removed ?

Or does it remain reserved?

  @SergioPichu 

Hi, the OpenVPN settings can be restored.

If you do not reset the second router, the settings should not disappear automatically.