Hi @theskid31 ,
It sounds like you are trying to get a variant of Wake on WAN or Wake on Internet working which doesn't sound like a great idea.
https://en.m.wikipedia.org/wiki/Wake-on-LAN
Presumably it's an internal server you wish to power on and best practice would be to have an always-on management host inside your LAN to control the power of other machines by BMC/IPMI or WOL.
In the same way that it's bad security practice to expose your BMC to the internet, you don't really want to expose WOL to the internet, even if it were possible.
Regardless of whether you want remote access to an internal management host, you would want to test that port forwarding is working for you from the internet (separate device with independent internet connection and interface outside your LAN) and under Linux, SSH is by far the safest test. There should be an equivalent safe test for Windows 10 and HTTP/80 and HTTPS/443 come to mind.
If your Wake-on-LAN functionality works at L2, you are forced to use an internal host.
If your subnet is a /24, which is the default on many consumer routers, x.x.x.255 is a broadcast address and not a valid host address.
It's not at all clear to me that a port forward can hit a broadcast address from the internet (could be router-dependent or entirely invalid). If you did intend to hit a broadcast address, this would be another good reason to remote into a management host first.
