18.101.90.56/31
PublicClass A — /31 prefix — 2 usable hosts
Network Address
18.101.90.56
Broadcast Address
18.101.90.57
Subnet Mask
255.255.255.254
Usable Hosts
2
First Usable IP
18.101.90.56
Last Usable IP
18.101.90.57
Total IPs
2
Prefix Length
Network address — the base address of the block (18.101.90.56). All devices in this subnet share this prefix. Cannot be assigned to a host.
Broadcast address — packets sent to 18.101.90.57 are delivered to every device in the subnet. Also reserved — not assignable.
Usable hosts — the 2 addresses between those two that you can assign to servers, VMs, or interfaces.
Subnet mask — 255.255.255.254 is the dotted-decimal equivalent of /31. Older tools and Cisco configs use this format instead of CIDR slash notation.
Full Details
| CIDR Notation | 18.101.90.56/31 |
| Network Address | 18.101.90.56 |
| Broadcast Address | 18.101.90.57 |
| Subnet Mask | 255.255.255.254 |
| Wildcard Mask | 0.0.0.1 |
| Prefix Length | /31 |
| IP Address Class | Class A |
| Total IP Addresses | 2 |
| Usable Host Addresses | 2 |
| First Usable IP | 18.101.90.56 |
| Last Usable IP | 18.101.90.57 |
| Network (Hex) | 0x12655A38 |
| Broadcast (Hex) | 0x12655A39 |
| Address Type | Public / Globally Routable |
Binary Representation
Network Address
00010010.01100101.01011010
00010010.01100101.01011010.00111000
Subnet Mask
11111111.11111111.11111111.11111110
The first 31 bits (1s in the mask) identify the network. The remaining 1 bits identify hosts within the network.
All 2 IP Addresses in this Range
18.101.90.56
net
18.101.90.57
bcast
/31 Subnet Reference
Total IPs
2
Usable Hosts
2
Subnet Mask
255.255.255.254
Wildcard
0.0.0.1