/32 Subnet
A /32 has the subnet mask 255.255.255.255 and contains 1 IP address. Every other prefix is in the subnet cheat sheet.
All 4 /32 Ranges in a /30
192.168.0.0/30 divides into 4 /32 subnets of 1 address each. The same pattern repeats in any /30: only the leading octets change.
| Network | Usable Range | Broadcast |
|---|---|---|
| 192.168.0.0/32 | 192.168.0.0 | — |
| 192.168.0.1/32 | 192.168.0.1 | — |
| 192.168.0.2/32 | 192.168.0.2 | — |
| 192.168.0.3/32 | 192.168.0.3 | — |
About /32 Networks
Host route — identifies a single device. A /32 subnet uses the mask 255.255.255.255 and provides 1 usable host addresses out of 1 total IPs.
Example /32 Networks
| Network | Broadcast | First Host | Last Host |
|---|---|---|---|
| 10.0.0.0/32 | 10.0.0.0 | 10.0.0.0 | 10.0.0.0 |
| 172.16.0.0/32 | 172.16.0.0 | 172.16.0.0 | 172.16.0.0 |
| 192.168.0.0/32 | 192.168.0.0 | 192.168.0.0 | 192.168.0.0 |
| 192.168.1.0/32 | 192.168.1.0 | 192.168.1.0 | 192.168.1.0 |
| 8.8.8.0/32 | 8.8.8.0 | 8.8.8.0 | 8.8.8.0 |
How Many /32 Subnets Fit in a Larger Network
The same arithmetic read the other way: how many /32 subnets you get when you carve up each of the next larger prefixes.
Adjacent CIDRs
Comparing sizes? The full /0 to /32 cheat sheet table puts every prefix side by side.
Frequently Asked Questions
What is a /32 subnet?
A /32 subnet uses the subnet mask 255.255.255.255 with 1 usable host addresses and 1 total IP addresses. It has 32 network bits and 0 host bits.
How many IP addresses are in a /32?
A /32 contains 1 IP address, of which 1 is a usable host. A /32 is a special case: it has no separate network or broadcast address.
What subnet mask does /32 use?
A /32 subnet uses the mask 255.255.255.255 (wildcard mask 0.0.0.0). This means the first 32 bits identify the network and the remaining 0 bits identify hosts.
How many /32 subnets are in a /31?
A /31 holds 2 /32 subnets. Each step to a shorter prefix doubles that count, because one bit moves from the host portion of the address to the network portion.
Standards
The figures on this page follow from the following specifications rather than from convention.
- RFC 4632 — Classless Inter-Domain Routing (CIDR)
Defines the /32 prefix notation used throughout this page, and the address-aggregation model that replaced classful addressing.
- RFC 950 — Internet Standard Subnetting Procedure
The original definition of the subnet mask, and of the network and broadcast addresses excluded from the usable host count.
- RFC 1918 — Address Allocation for Private Internets
Reserves 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16, the ranges most /32 subnets are carved from in practice.