IPv4 subnet cheat sheet
Every prefix length from /32 to /8: netmask, number of addresses, usable hosts and how many /24s it holds.
| Prefix | Netmask | Addresses | Usable hosts | /24 blocks |
|---|
/31 is used for point-to-point links (2 usable), /32 for a single host. Try any prefix in the subnet calculator.