How many usable IP addresses are in a /32 subnet?

A /32 subnet contains 1 total IP addresses. In standard networking, 2 addresses are reserved (the Network ID and Broadcast address), leaving 1 usable host IP addresses.

What is the wildcard mask for /32?

The wildcard mask for /32 (255.255.255.255) is 0.0.0.0. Wildcard masks are commonly used in Cisco IOS Access Control Lists (ACLs) and OSPF routing configurations.

Home/Subnet Calculator//32 CIDR

/31

IPv4 CIDR Reference

/32 Subnet Mask — 255.255.255.255 Netmask & Host Calculator

A /32 subnet prefix allocates 255.255.255.255 as its subnet mask. It provides 1 total IPv4 addresses and 1 usable host addresses with a wildcard mask of 0.0.0.0.

Subnet Mask

255.255.255.255

Usable Hosts

Total Addresses

Wildcard Mask

0.0.0.0

Interactive /32 Subnet Calculator

Binary Architecture of a /32 Mask

An IPv4 address consists of 32 bits. In a /32 prefix, the first 32 bits are locked as binary 1s (representing the network prefix), while the remaining 0 bits are binary 0s (reserved for host assignment).

Prefix Length: /32

Binary Mask: 11111111.11111111.11111111.11111111

Dotted Decimal: 255.255.255.255

Formula: 2^(32 - 32) = 1 IPs

When Should You Use a /32 Subnet?

Single host loopback address or specific host firewall route.

Optimized for low-waste routing and efficient IP allocation.

Frequently Asked Questions about /32 Subnets

The subnet mask for a /32 CIDR prefix is 255.255.255.255. In binary notation, this is 11111111.11111111.11111111.11111111 (32 contiguous network bits and 0 host bits).