IP CIDR rules and address ranges

I always forget IP address range coverage rules and forget where to look.

It’s the wiki!

https://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing

and for good reference here is the table:

/32 is for a single address

/24 is for a range in the last place x.x.x.0

/16 is for a range in the last 2 places x.x.0.0