@alexhaydock oh btw if your internet connection (the hardwired one) is a&a, please note that a&a also provides l2tp for free with all their hardlines (e.g. PPPoE on adsl, vdsl, fttp).
the l2tp becomes active when your main hardline is down, and you can use it from another ISP to do failover.
https://support.aa.net.uk/Router:Linux_-_Debian_-_With_L2TP_Fallback
This guide is for those using a *hardline*.
I don't use an a&a hardline at my lab. i'm using another ISP that offers much faster upload speed. I use a&a's standalone l2tp service.