cloudflare-dynamic-dns VS ddns-updater

You could add a specific rule to the firewall that allows a single address to connect, on top of your country-geo-block. I have this set up with Cloudflare, where a single script is run the minute I know the IP of the client (e.g. on the client itself). This will update a subdomain-DNS only entry on cloudflare with the current IP (e.g. iuwqziudjsbdabdsab.mytld.com). The firewall is set to allow connections from iuwqziudjsbdabdsab.mytld.com and will periodically check the IP of this address.

Setup https://github.com/qdm12/ddns-updater to keep you IP address updated for your Google DNS record. This is only need for inbound access while you are remote so that your DNS record is updated if you IP address changes.

Do you mean something like ddns-updater?

This assumes you have your DynDNS mechanism set up by any means other than the Fritz!Box internals (for example, I use this docker image, in combination with my cloudflare managed domain to achieve DDNS behavior). This means that the Fritz!Box needs to be reachable with the domain you intend to use for your VPN connection. For example, I use vpn...

SOLVED: Thanks to some of the suggestions here I realized the WAN IP wasn't actually changing. The DDNS updater I use: https://github.com/qdm12/ddns-updater uses a bunch of different sources, both http and DNS to determine the current public IP. At lease one of the http sources was no longer working and I have no idea how the DNS sources are supposed to know what my current IP is, that doesn't make sense to me.

I use ddns-updater.

Take a look at qdm12/ddns-updater

Use https://github.com/qdm12/ddns-updater. You can buy a standard domain, and this will keep it pointed at your IP.

if youre public IP isnt static, you will need a dns-updater too.

Use a dynamic DNS service like noip.com. You either use one of their domains like myusername.someDDNScompany.com or you use your own domain. Then you run software like ddns_updater on a raspberry pi or a docker container on your NAS that periodically checks and updates the DNS record with your current home IP.