How many IPs are in any given ISP's pool for DHCP?

Question

I would assume that there are a lot. For example, with Verizon the first two numbers 70.105 never seem to change. The last two, seem to change as the DHCP lease changes. I was wondering how many are in a given pool?

Also, would I be right in assuming that perhaps the 70.105 signify the location of the pool for instance where I am located and that would be why they don't change?

This is a semi deep technical question, so please respond only if you know what you're talking about. Thanks!

Answer 1

16,777,214 hosts on each Class A address.

Class A 1.0.0.1 to 126.255.255.254 Supports 16 million hosts on each of 127 networks.

Class B 128.1.0.1 to 191.255.255.254 Supports 65,000 hosts on each of 16,000 networks.

Class C 192.0.1.1 to 223.255.254.254 Supports 254 hosts on each of 2 million networks.