NumPy:

Does the Fritzbox not also do this?

Ironicly, a friend gave me a Fritzbox the day before lockdown (I was running round madly getting neighbours Internet and TV going). Haven't touched it since. Looks like I need an analouge phone to reset it! (I do have such a beast, in a far corner of the ark!)
Will have a look, but @Jase2985 has given me a perfectly good solution! Still interesting.