/30 Subnet Mask Reference

The subnet mask for prefix length /30 is 255.255.255.252. Minimal subnet — ideal for point-to-point WAN links. 2 usable hosts.

Prefix Length/30
Subnet Mask255.255.255.252
Wildcard Mask0.0.0.3
Hex ValueFFFFFFFC
Usable Hosts2
Network Bits30 / 32

Binary Representation

Subnet Mask11111111.11111111.11111111.11111100
Wildcard Mask00000000.00000000.00000000.00000011

1-bits (network): 30 ·  0-bits (host): 2 ·  Total: 32 bits

Common Uses for 255.255.255.252

  • Point-to-point link (2 hosts)
  • Router-to-router WAN link
  • Most efficient for P2P

Frequently Asked Questions

What is the subnet mask for /30?

The subnet mask for prefix length /30 is 255.255.255.252. In hexadecimal it is 0xFFFFFFFC. The binary representation is 11111111.11111111.11111111.11111100.

What is the inverse (wildcard) mask of 255.255.255.252?

The wildcard mask (inverse mask) of 255.255.255.252 is 0.0.0.3. 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 255.255.255.252 give?

With subnet mask 255.255.255.252 (/30), you get 4 total IPs, minus 2 reserved (network + broadcast) = 2 usable host addresses.

What CIDR prefix corresponds to 255.255.255.252?

The subnet mask 255.255.255.252 corresponds to CIDR prefix /30. This means 30 bits are used for the network portion and 2 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