Special Purpose IPv4 Address Space
Non-usable IPv4 address space is:
- 0/8
- 10/8 Private Use
- 127/8
- 169.254/16
- 172.16/12
- 192.0.2/24
- 192.168/16
- 224/3 -?
240 through to 255 (IANA Reserved) - strictly historical class E space - not clear if there are any plans to do anything with it.
the remaining address space is assumed to be usable.