/32 Subnet Mask Reference

The subnet mask for prefix length /32 is 255.255.255.255. Host route — represents a single specific IP address.

Prefix Length/32
Subnet Mask255.255.255.255
Wildcard Mask0.0.0.0
Hex ValueFFFFFFFF
Usable Hosts1
Network Bits32 / 32

Binary Representation

Subnet Mask11111111.11111111.11111111.11111111
Wildcard Mask00000000.00000000.00000000.00000000

1-bits (network): 32 ·  0-bits (host): 0 ·  Total: 32 bits

Common Uses for 255.255.255.255

  • Single host route
  • Loopback (/32 = specific host)
  • Blackhole routing

Frequently Asked Questions

What is the subnet mask for /32?

The subnet mask for prefix length /32 is 255.255.255.255. In hexadecimal it is 0xFFFFFFFF. The binary representation is 11111111.11111111.11111111.11111111.

What is the inverse (wildcard) mask of 255.255.255.255?

The wildcard mask (inverse mask) of 255.255.255.255 is 0.0.0.0. Wildcard masks are used in Cisco IOS ACLs and OSPF configurations to specify which bits of an IP address to match.

How many host IPs does 255.255.255.255 give?

The /32 prefix provides 1 host address (special case: no traditional network/broadcast separation).

What CIDR prefix corresponds to 255.255.255.255?

The subnet mask 255.255.255.255 corresponds to CIDR prefix /32. This means 32 bits are used for the network portion and 0 bits for host addresses.

Complete Subnet Mask Reference /0–/32

PrefixSubnet MaskWildcardHexUsable Hosts
/00.0.0.0255.255.255.255000000004.294.967.294
/1128.0.0.0127.255.255.255800000002.147.483.646
/2192.0.0.063.255.255.255C00000001.073.741.822
/3224.0.0.031.255.255.255E0000000536.870.910
/4240.0.0.015.255.255.255F0000000268.435.454
/5248.0.0.07.255.255.255F8000000134.217.726
/6252.0.0.03.255.255.255FC00000067.108.862
/7254.0.0.01.255.255.255FE00000033.554.430
/8255.0.0.00.255.255.255FF00000016.777.214
/9255.128.0.00.127.255.255FF8000008.388.606
/10255.192.0.00.63.255.255FFC000004.194.302
/11255.224.0.00.31.255.255FFE000002.097.150
/12255.240.0.00.15.255.255FFF000001.048.574
/13255.248.0.00.7.255.255FFF80000524.286
/14255.252.0.00.3.255.255FFFC0000262.142
/15255.254.0.00.1.255.255FFFE0000131.070
/16255.255.0.00.0.255.255FFFF000065.534
/17255.255.128.00.0.127.255FFFF800032.766
/18255.255.192.00.0.63.255FFFFC00016.382
/19255.255.224.00.0.31.255FFFFE0008.190
/20255.255.240.00.0.15.255FFFFF0004.094
/21255.255.248.00.0.7.255FFFFF8002.046
/22255.255.252.00.0.3.255FFFFFC001.022
/23255.255.254.00.0.1.255FFFFFE00510
/24255.255.255.00.0.0.255FFFFFF00254
/25255.255.255.1280.0.0.127FFFFFF80126
/26255.255.255.1920.0.0.63FFFFFFC062
/27255.255.255.2240.0.0.31FFFFFFE030
/28255.255.255.2400.0.0.15FFFFFFF014
/29255.255.255.2480.0.0.7FFFFFFF86
/30255.255.255.2520.0.0.3FFFFFFFC2
/31255.255.255.2540.0.0.1FFFFFFFE2
/32255.255.255.2550.0.0.0FFFFFFFF1