255.255.255.254 Subnet Mask
255.255.255.254 is the subnet mask for a /31 network — 2 usable hosts out of 2 addresses.
CIDR Prefix
/31
Wildcard Mask
0.0.0.1
Total Addresses
2
Usable Hosts
2
Network Bits
31
Host Bits
1
255.255.255.254 in Binary
Each octet is eight bits. The highlighted bits are the 31 network bits; the rest are the 1 host bits that vary within the subnet.
255
255
255
254
Networks Using 255.255.255.254
| Network | Host Range | Broadcast |
|---|---|---|
| 10.0.0.0/31 | 10.0.0.0 – 10.0.0.1 | 10.0.0.1 |
| 172.16.0.0/31 | 172.16.0.0 – 172.16.0.1 | 172.16.0.1 |
| 192.168.1.0/31 | 192.168.1.0 – 192.168.1.1 | 192.168.1.1 |
Neighbouring Masks
Frequently Asked Questions
What CIDR prefix is 255.255.255.254?
255.255.255.254 is /31 in CIDR notation. The mask sets the first 31 of the 32 bits in an IPv4 address to 1, marking them as the network portion, and leaves the remaining 1 bits as 0 for hosts.
How many hosts does 255.255.255.254 allow?
A network with mask 255.255.255.254 holds 2 addresses, of which 2 are usable by hosts. A /31 has no broadcast address to reserve, per RFC 3021, so both addresses are usable on a point-to-point link.
What is the wildcard mask for 255.255.255.254?
The wildcard mask for 255.255.255.254 is 0.0.0.1. It is the bitwise inverse: every 1 in the subnet mask becomes a 0 and every 0 becomes a 1. Cisco access lists and OSPF network statements take the wildcard form rather than the subnet mask.
Standards
- RFC 950 — Internet Standard Subnetting Procedure
Defines the dotted-decimal subnet mask itself, and the rule that the network and broadcast addresses are not assignable to hosts.
- RFC 4632 — Classless Inter-Domain Routing (CIDR)
Establishes the /31 prefix notation that 255.255.255.254 is equivalent to, and requires masks to be contiguous — which is why exactly 33 of the 4.3 billion possible values are valid.