151.8.240.0/20
PublicClass B — /20 prefix — 4,094 usable hosts
Network address — the base address of the block (151.8.240.0). All devices in this subnet share this prefix. Cannot be assigned to a host.
Broadcast address — packets sent to 151.8.255.255 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 | 151.8.240.0/20 |
| Network Address | 151.8.240.0 |
| Broadcast Address | 151.8.255.255 |
| 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 | 151.8.240.1 |
| Last Usable IP | 151.8.255.254 |
| Network (Hex) | 0x9708F000 |
| Broadcast (Hex) | 0x9708FFFF |
| Address Type | Public / Globally Routable |
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 151.8.240.0/20 into 2 equal /21 subnets (2,046 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 151.8.240.0/21 | 151.8.240.0 | 151.8.240.1 | 151.8.247.254 | 151.8.247.255 | 2,046 |
| 2 | 151.8.248.0/21 | 151.8.248.0 | 151.8.248.1 | 151.8.255.254 | 151.8.255.255 | 2,046 |
Split 151.8.240.0/20 into 4 equal /22 subnets (1,022 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 151.8.240.0/22 | 151.8.240.0 | 151.8.240.1 | 151.8.243.254 | 151.8.243.255 | 1,022 |
| 2 | 151.8.244.0/22 | 151.8.244.0 | 151.8.244.1 | 151.8.247.254 | 151.8.247.255 | 1,022 |
| 3 | 151.8.248.0/22 | 151.8.248.0 | 151.8.248.1 | 151.8.251.254 | 151.8.251.255 | 1,022 |
| 4 | 151.8.252.0/22 | 151.8.252.0 | 151.8.252.1 | 151.8.255.254 | 151.8.255.255 | 1,022 |
Split 151.8.240.0/20 into 8 equal /23 subnets (510 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 151.8.240.0/23 | 151.8.240.0 | 151.8.240.1 | 151.8.241.254 | 151.8.241.255 | 510 |
| 2 | 151.8.242.0/23 | 151.8.242.0 | 151.8.242.1 | 151.8.243.254 | 151.8.243.255 | 510 |
| 3 | 151.8.244.0/23 | 151.8.244.0 | 151.8.244.1 | 151.8.245.254 | 151.8.245.255 | 510 |
| 4 | 151.8.246.0/23 | 151.8.246.0 | 151.8.246.1 | 151.8.247.254 | 151.8.247.255 | 510 |
| 5 | 151.8.248.0/23 | 151.8.248.0 | 151.8.248.1 | 151.8.249.254 | 151.8.249.255 | 510 |
| 6 | 151.8.250.0/23 | 151.8.250.0 | 151.8.250.1 | 151.8.251.254 | 151.8.251.255 | 510 |
| 7 | 151.8.252.0/23 | 151.8.252.0 | 151.8.252.1 | 151.8.253.254 | 151.8.253.255 | 510 |
| 8 | 151.8.254.0/23 | 151.8.254.0 | 151.8.254.1 | 151.8.255.254 | 151.8.255.255 | 510 |
Split 151.8.240.0/20 into 16 equal /24 subnets (254 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 151.8.240.0/24 | 151.8.240.0 | 151.8.240.1 | 151.8.240.254 | 151.8.240.255 | 254 |
| 2 | 151.8.241.0/24 | 151.8.241.0 | 151.8.241.1 | 151.8.241.254 | 151.8.241.255 | 254 |
| 3 | 151.8.242.0/24 | 151.8.242.0 | 151.8.242.1 | 151.8.242.254 | 151.8.242.255 | 254 |
| 4 | 151.8.243.0/24 | 151.8.243.0 | 151.8.243.1 | 151.8.243.254 | 151.8.243.255 | 254 |
| 5 | 151.8.244.0/24 | 151.8.244.0 | 151.8.244.1 | 151.8.244.254 | 151.8.244.255 | 254 |
| 6 | 151.8.245.0/24 | 151.8.245.0 | 151.8.245.1 | 151.8.245.254 | 151.8.245.255 | 254 |
| 7 | 151.8.246.0/24 | 151.8.246.0 | 151.8.246.1 | 151.8.246.254 | 151.8.246.255 | 254 |
| 8 | 151.8.247.0/24 | 151.8.247.0 | 151.8.247.1 | 151.8.247.254 | 151.8.247.255 | 254 |
| 9 | 151.8.248.0/24 | 151.8.248.0 | 151.8.248.1 | 151.8.248.254 | 151.8.248.255 | 254 |
| 10 | 151.8.249.0/24 | 151.8.249.0 | 151.8.249.1 | 151.8.249.254 | 151.8.249.255 | 254 |
| 11 | 151.8.250.0/24 | 151.8.250.0 | 151.8.250.1 | 151.8.250.254 | 151.8.250.255 | 254 |
| 12 | 151.8.251.0/24 | 151.8.251.0 | 151.8.251.1 | 151.8.251.254 | 151.8.251.255 | 254 |
| 13 | 151.8.252.0/24 | 151.8.252.0 | 151.8.252.1 | 151.8.252.254 | 151.8.252.255 | 254 |
| 14 | 151.8.253.0/24 | 151.8.253.0 | 151.8.253.1 | 151.8.253.254 | 151.8.253.255 | 254 |
| 15 | 151.8.254.0/24 | 151.8.254.0 | 151.8.254.1 | 151.8.254.254 | 151.8.254.255 | 254 |
| 16 | 151.8.255.0/24 | 151.8.255.0 | 151.8.255.1 | 151.8.255.254 | 151.8.255.255 | 254 |