/32 subnet.

What does /32 mean?

IPv4 addresses contain 32 bits. A /32 CIDR prefix means the first 32 bits identify the network and the remaining 0 bits identify addresses within that network. Because there are 0 host bits, the block contains 2⁰, or 1, total IPv4 address. In practical terms, /32 is a single-address prefix used to identify one exact IPv4 host or route.

/32 subnet mask

The dotted-decimal subnet mask for /32 is 255.255.255.255. Its inverse wildcard mask is 0.0.0.0. These are different notations for the same network/host boundary: the subnet mask marks network bits with ones, while the wildcard mask flips those bits.

How many hosts are in a /32?

A /32 identifies exactly one IPv4 address, typically representing a single host or route rather than a multi-host subnet.

How /32 boundaries behave

Within a /24-style final-octet view, /32 blocks advance in increments of 1 address when the prefix is at least /24. This makes network boundaries predictable and easy to verify. Increasing the prefix to /32 cannot make the prefix more specific because /32 already identifies a single address. Decreasing it to /31 combines this address space with an adjacent block of the same size.

When would you use a /32?

The right prefix depends on route aggregation, host requirements, topology and operational policy rather than on a single universal rule. Large prefixes with smaller numbers represent broad address aggregates; prefixes closer to /32 represent progressively smaller blocks. For ordinary IPv4 LAN planning, always verify that the chosen prefix has enough conventional usable host addresses and leaves appropriate room for growth.

Compare nearby CIDR prefixes

Frequently asked questions

Use the interactive calculator below with a real IPv4 address, or open the complete subnetting cheat sheet to compare /32 with every other CIDR size.