Say I have the private network address 172.16.0.0/12 and I want to split it into 2 subnets.
There are 12 bits used for the network number leaving 20 bit for the host number. I use 1 of these host bits as a subnet number giving me 2 subnets and leaving me with 19 bits for the host number.
This will mean I will have 2^19 - 2 = 524286 IP addresses per subnet?
And the second subnet address will be 172.24.0.0. The broadcast address of the second subnet will be 172.31.255.255
Have I got that correct?