I didn't know that existed. Seems like a good alternative, thanks. I prefer the whitelist for my own personal usage as it applies to all my servers/VM in one go

I didn't know that existed. Seems like a good alternative, thanks. I prefer the whitelist for my own personal usage as it applies to all my servers/VM in one go for all ports. But agree that's a simpler solution if you have a single port+machine to protect.