More detailsNeighboring subnets, wildcard mask, hex, reverse DNS, and binary breakdown
Neighboring /32 subnets
- Wildcard mask
- Used in Cisco ACLs and OSPF
- CIDR notation
- IP in hexadecimal
- IP as 32-bit integer
- Reverse DNS (PTR)
- Host bits / subnet bits
Binary breakdown
IP address
11000000.10101000.00000001.00000001Subnet mask
11111111.11111111.11111111.11111111Network
11000000.10101000.00000001.00000001Broadcast
11000000.10101000.00000001.00000001Quick facts for /32
- Subnet mask: 255.255.255.255
- Wildcard: 0.0.0.0
- Usable hosts: 1
- Total addresses: 1
/32 reference guideBit split, overview, sizing tables, notable networks, and FAQ
Binary bit split
11111111·11111111·11111111·11111111
Network bits (32)Host bits (0)
- Network bits
- 32
- Host bits
- 0
- Subnet mask
- 255.255.255.255
- Wildcard mask
- 0.0.0.0
- Total addresses
- 1
- Usable hosts
- 1
- Hosts formula
- 1 host route
- /24 relationship
- 256 fit per /24
Overview
A /32 is a host route — it identifies exactly one IP address. It is used in routing tables to add a specific route to a single host, in firewall rules to permit or deny one IP, and for loopback interfaces.
Common use cases
- Static host routes in routing tables
- Firewall rules targeting a single IP
- Loopback interface addressing (e.g. 10.255.255.1/32)
- BGP next-hop resolution
- Cloud security group rules for one host
Subnet sizing reference
Notable /32 networks
127.0.0.1/32IPv4 loopback (localhost)192.168.1.1/32Single host route example
Frequently asked questions
Common questions about /32 networks, subnet masks, and use cases.