I've made my own DDNS service and it works fine using an application running on clients to update the IP. But if for some reason I don't have the choice of using my software and instead I need to use a router to update the IP, it becomes troublesome.

For example, I needed to setup IPsec from a customer to me and the customers router/firewall (netgear srx5308) has a dynamic IP which is given from the ISP which can't offer static IPs. So it needs to use dynamic dns for it to work. In this case there really isn't a client to run the software on since it's a router/firewall. Unfortunately it seems that most routers are rather unfriendly towards custom DDNS solutions and most offer only dyndns.com or similar templates. Which was the case with this router too. Leaving me with no way to use my own dynamic dns server IP.

I have the option of switching out the customers router and I've been looking around for alternatives and other routers/solutions and I was wondering if anyone on this great site might have been in a similar situation or might just know about some router/firewall that is more friendly towards custom ddns solutions that I might be able to use.

Thanks in advance for any help or guidance!