DDNS : Allow private ip configuration

Hi. I have a device on my LAN with a private IP that changes it's IP from time to time. However I would like to use duckDNS with this private IP (to generate a let's encrypt certificate).

I've made a script on the router to retrive the private IP of the device through 'dig +short' however the DDNS script is not letting me call the duckDNS URL (or even a custom URL) because "No or private or invalid IP" detected.

Is there a way to force the update, as, in this case it, retrieving a private IP is the intended behavior ?

Thank you.

I guess you should use your public IP and domain for DDNS and ACME respectively.
Meanwhile, you can rebind the domain to a private IP on the local DNS server.

Thanks. That would work in many cases. But not in mine :frowning:
I actually want to be able to switch my main router (handling the DNS) and replace it with the buggy piece of c*** that my ISP provides from time to time. If I switch to the ISP box, the DHCP leases are not stored (because of its countless bugs...) so rebinding to the old IP won't help much.

The DDNS script is running on a openwrt wifi hotspot that stays in place regardless of the WAN router being openWRT or ISP box.

I know that giving static IPs to the server could also solve the issue, but I find that centralizing all my static DHCP leases on one place is more convenient. I was just wondering if there was a hidden setting somewhere to override this private ip verification.

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Can you edit the script to disable the check?

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Even if DDNS allows to use a private IP, are you sure both duckDNS and LetsEncrypt are going to accept it?

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Yes I have this exact setup working with DuckDNS and let's encrypt on a private IP.

Thank you for the suggestion. I could indeed. But it seems less hacky to me in that case to set static IPs on the servers. At least it will survive upgrades of openWRT.

DDNS is handled by some scripts, that do not seem too hard to modify, and disable the check.

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