172.31.144.0/20
Private (RFC 1918) RFC 1918Class B — /20 prefix — 4,094 usable hosts
Network address — the base address of the block (172.31.144.0). All devices in this subnet share this prefix. Cannot be assigned to a host.
Broadcast address — packets sent to 172.31.159.255 are delivered to every device in the subnet. Also reserved — not assignable.
Usable hosts — the 4,094 addresses between those two that you can assign to servers, VMs, or interfaces.
Subnet mask — 255.255.240.0 is the dotted-decimal equivalent of /20. Older tools and Cisco configs use this format instead of CIDR slash notation.
Full Details
| CIDR Notation | 172.31.144.0/20 |
| Network Address | 172.31.144.0 |
| Broadcast Address | 172.31.159.255 |
| Subnet Mask | 255.255.240.0 |
| Wildcard Mask | 0.0.15.255 |
| Prefix Length | /20 |
| IP Address Class | Class B |
| Total IP Addresses | 4,096 |
| Usable Host Addresses | 4,094 |
| First Usable IP | 172.31.144.1 |
| Last Usable IP | 172.31.159.254 |
| Network (Hex) | 0xAC1F9000 |
| Broadcast (Hex) | 0xAC1F9FFF |
| Governing RFC | RFC 1918 |
| Address Type | Private (RFC 1918) |
Binary Representation
The first 20 bits (1s in the mask) identify the network. The remaining 12 bits identify hosts within the network.
Split into Equal Subnets
Split 172.31.144.0/20 into 2 equal /21 subnets (2,046 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 172.31.144.0/21 | 172.31.144.0 | 172.31.144.1 | 172.31.151.254 | 172.31.151.255 | 2,046 |
| 2 | 172.31.152.0/21 | 172.31.152.0 | 172.31.152.1 | 172.31.159.254 | 172.31.159.255 | 2,046 |
Split 172.31.144.0/20 into 4 equal /22 subnets (1,022 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 172.31.144.0/22 | 172.31.144.0 | 172.31.144.1 | 172.31.147.254 | 172.31.147.255 | 1,022 |
| 2 | 172.31.148.0/22 | 172.31.148.0 | 172.31.148.1 | 172.31.151.254 | 172.31.151.255 | 1,022 |
| 3 | 172.31.152.0/22 | 172.31.152.0 | 172.31.152.1 | 172.31.155.254 | 172.31.155.255 | 1,022 |
| 4 | 172.31.156.0/22 | 172.31.156.0 | 172.31.156.1 | 172.31.159.254 | 172.31.159.255 | 1,022 |
Split 172.31.144.0/20 into 8 equal /23 subnets (510 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 172.31.144.0/23 | 172.31.144.0 | 172.31.144.1 | 172.31.145.254 | 172.31.145.255 | 510 |
| 2 | 172.31.146.0/23 | 172.31.146.0 | 172.31.146.1 | 172.31.147.254 | 172.31.147.255 | 510 |
| 3 | 172.31.148.0/23 | 172.31.148.0 | 172.31.148.1 | 172.31.149.254 | 172.31.149.255 | 510 |
| 4 | 172.31.150.0/23 | 172.31.150.0 | 172.31.150.1 | 172.31.151.254 | 172.31.151.255 | 510 |
| 5 | 172.31.152.0/23 | 172.31.152.0 | 172.31.152.1 | 172.31.153.254 | 172.31.153.255 | 510 |
| 6 | 172.31.154.0/23 | 172.31.154.0 | 172.31.154.1 | 172.31.155.254 | 172.31.155.255 | 510 |
| 7 | 172.31.156.0/23 | 172.31.156.0 | 172.31.156.1 | 172.31.157.254 | 172.31.157.255 | 510 |
| 8 | 172.31.158.0/23 | 172.31.158.0 | 172.31.158.1 | 172.31.159.254 | 172.31.159.255 | 510 |
Split 172.31.144.0/20 into 16 equal /24 subnets (254 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 172.31.144.0/24 | 172.31.144.0 | 172.31.144.1 | 172.31.144.254 | 172.31.144.255 | 254 |
| 2 | 172.31.145.0/24 | 172.31.145.0 | 172.31.145.1 | 172.31.145.254 | 172.31.145.255 | 254 |
| 3 | 172.31.146.0/24 | 172.31.146.0 | 172.31.146.1 | 172.31.146.254 | 172.31.146.255 | 254 |
| 4 | 172.31.147.0/24 | 172.31.147.0 | 172.31.147.1 | 172.31.147.254 | 172.31.147.255 | 254 |
| 5 | 172.31.148.0/24 | 172.31.148.0 | 172.31.148.1 | 172.31.148.254 | 172.31.148.255 | 254 |
| 6 | 172.31.149.0/24 | 172.31.149.0 | 172.31.149.1 | 172.31.149.254 | 172.31.149.255 | 254 |
| 7 | 172.31.150.0/24 | 172.31.150.0 | 172.31.150.1 | 172.31.150.254 | 172.31.150.255 | 254 |
| 8 | 172.31.151.0/24 | 172.31.151.0 | 172.31.151.1 | 172.31.151.254 | 172.31.151.255 | 254 |
| 9 | 172.31.152.0/24 | 172.31.152.0 | 172.31.152.1 | 172.31.152.254 | 172.31.152.255 | 254 |
| 10 | 172.31.153.0/24 | 172.31.153.0 | 172.31.153.1 | 172.31.153.254 | 172.31.153.255 | 254 |
| 11 | 172.31.154.0/24 | 172.31.154.0 | 172.31.154.1 | 172.31.154.254 | 172.31.154.255 | 254 |
| 12 | 172.31.155.0/24 | 172.31.155.0 | 172.31.155.1 | 172.31.155.254 | 172.31.155.255 | 254 |
| 13 | 172.31.156.0/24 | 172.31.156.0 | 172.31.156.1 | 172.31.156.254 | 172.31.156.255 | 254 |
| 14 | 172.31.157.0/24 | 172.31.157.0 | 172.31.157.1 | 172.31.157.254 | 172.31.157.255 | 254 |
| 15 | 172.31.158.0/24 | 172.31.158.0 | 172.31.158.1 | 172.31.158.254 | 172.31.158.255 | 254 |
| 16 | 172.31.159.0/24 | 172.31.159.0 | 172.31.159.1 | 172.31.159.254 | 172.31.159.255 | 254 |