0.0.0.0/1
PublicClass A — /1 prefix — 2,147,483,646 usable hosts
Network address — the base address of the block (0.0.0.0). All devices in this subnet share this prefix. Cannot be assigned to a host.
Broadcast address — packets sent to 127.255.255.255 are delivered to every device in the subnet. Also reserved — not assignable.
Usable hosts — the 2,147,483,646 addresses between those two that you can assign to servers, VMs, or interfaces.
Subnet mask — 128.0.0.0 is the dotted-decimal equivalent of /1. Older tools and Cisco configs use this format instead of CIDR slash notation.
Full Details
| CIDR Notation | 0.0.0.0/1 |
| Network Address | 0.0.0.0 |
| Broadcast Address | 127.255.255.255 |
| Subnet Mask | 128.0.0.0 |
| Wildcard Mask | 127.255.255.255 |
| Prefix Length | /1 |
| IP Address Class | Class A |
| Total IP Addresses | 2,147,483,648 |
| Usable Host Addresses | 2,147,483,646 |
| First Usable IP | 0.0.0.1 |
| Last Usable IP | 127.255.255.254 |
| Network (Hex) | 0x00000000 |
| Broadcast (Hex) | 0x7FFFFFFF |
| Address Type | Public / Globally Routable |
Binary Representation
The first 1 bits (1s in the mask) identify the network. The remaining 31 bits identify hosts within the network.
Split into Equal Subnets
Split 0.0.0.0/1 into 2 equal /2 subnets (1,073,741,822 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 0.0.0.0/2 | 0.0.0.0 | 0.0.0.1 | 63.255.255.254 | 63.255.255.255 | 1,073,741,822 |
| 2 | 64.0.0.0/2 | 64.0.0.0 | 64.0.0.1 | 127.255.255.254 | 127.255.255.255 | 1,073,741,822 |
Split 0.0.0.0/1 into 4 equal /3 subnets (536,870,910 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 0.0.0.0/3 | 0.0.0.0 | 0.0.0.1 | 31.255.255.254 | 31.255.255.255 | 536,870,910 |
| 2 | 32.0.0.0/3 | 32.0.0.0 | 32.0.0.1 | 63.255.255.254 | 63.255.255.255 | 536,870,910 |
| 3 | 64.0.0.0/3 | 64.0.0.0 | 64.0.0.1 | 95.255.255.254 | 95.255.255.255 | 536,870,910 |
| 4 | 96.0.0.0/3 | 96.0.0.0 | 96.0.0.1 | 127.255.255.254 | 127.255.255.255 | 536,870,910 |
Split 0.0.0.0/1 into 8 equal /4 subnets (268,435,454 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 0.0.0.0/4 | 0.0.0.0 | 0.0.0.1 | 15.255.255.254 | 15.255.255.255 | 268,435,454 |
| 2 | 16.0.0.0/4 | 16.0.0.0 | 16.0.0.1 | 31.255.255.254 | 31.255.255.255 | 268,435,454 |
| 3 | 32.0.0.0/4 | 32.0.0.0 | 32.0.0.1 | 47.255.255.254 | 47.255.255.255 | 268,435,454 |
| 4 | 48.0.0.0/4 | 48.0.0.0 | 48.0.0.1 | 63.255.255.254 | 63.255.255.255 | 268,435,454 |
| 5 | 64.0.0.0/4 | 64.0.0.0 | 64.0.0.1 | 79.255.255.254 | 79.255.255.255 | 268,435,454 |
| 6 | 80.0.0.0/4 | 80.0.0.0 | 80.0.0.1 | 95.255.255.254 | 95.255.255.255 | 268,435,454 |
| 7 | 96.0.0.0/4 | 96.0.0.0 | 96.0.0.1 | 111.255.255.254 | 111.255.255.255 | 268,435,454 |
| 8 | 112.0.0.0/4 | 112.0.0.0 | 112.0.0.1 | 127.255.255.254 | 127.255.255.255 | 268,435,454 |
Split 0.0.0.0/1 into 16 equal /5 subnets (134,217,726 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 0.0.0.0/5 | 0.0.0.0 | 0.0.0.1 | 7.255.255.254 | 7.255.255.255 | 134,217,726 |
| 2 | 8.0.0.0/5 | 8.0.0.0 | 8.0.0.1 | 15.255.255.254 | 15.255.255.255 | 134,217,726 |
| 3 | 16.0.0.0/5 | 16.0.0.0 | 16.0.0.1 | 23.255.255.254 | 23.255.255.255 | 134,217,726 |
| 4 | 24.0.0.0/5 | 24.0.0.0 | 24.0.0.1 | 31.255.255.254 | 31.255.255.255 | 134,217,726 |
| 5 | 32.0.0.0/5 | 32.0.0.0 | 32.0.0.1 | 39.255.255.254 | 39.255.255.255 | 134,217,726 |
| 6 | 40.0.0.0/5 | 40.0.0.0 | 40.0.0.1 | 47.255.255.254 | 47.255.255.255 | 134,217,726 |
| 7 | 48.0.0.0/5 | 48.0.0.0 | 48.0.0.1 | 55.255.255.254 | 55.255.255.255 | 134,217,726 |
| 8 | 56.0.0.0/5 | 56.0.0.0 | 56.0.0.1 | 63.255.255.254 | 63.255.255.255 | 134,217,726 |
| 9 | 64.0.0.0/5 | 64.0.0.0 | 64.0.0.1 | 71.255.255.254 | 71.255.255.255 | 134,217,726 |
| 10 | 72.0.0.0/5 | 72.0.0.0 | 72.0.0.1 | 79.255.255.254 | 79.255.255.255 | 134,217,726 |
| 11 | 80.0.0.0/5 | 80.0.0.0 | 80.0.0.1 | 87.255.255.254 | 87.255.255.255 | 134,217,726 |
| 12 | 88.0.0.0/5 | 88.0.0.0 | 88.0.0.1 | 95.255.255.254 | 95.255.255.255 | 134,217,726 |
| 13 | 96.0.0.0/5 | 96.0.0.0 | 96.0.0.1 | 103.255.255.254 | 103.255.255.255 | 134,217,726 |
| 14 | 104.0.0.0/5 | 104.0.0.0 | 104.0.0.1 | 111.255.255.254 | 111.255.255.255 | 134,217,726 |
| 15 | 112.0.0.0/5 | 112.0.0.0 | 112.0.0.1 | 119.255.255.254 | 119.255.255.255 | 134,217,726 |
| 16 | 120.0.0.0/5 | 120.0.0.0 | 120.0.0.1 | 127.255.255.254 | 127.255.255.255 | 134,217,726 |