128.0.0.0/5
PublicClass B — /5 prefix — 134,217,726 usable hosts
Network address — the base address of the block (128.0.0.0). All devices in this subnet share this prefix. Cannot be assigned to a host.
Broadcast address — packets sent to 135.255.255.255 are delivered to every device in the subnet. Also reserved — not assignable.
Usable hosts — the 134,217,726 addresses between those two that you can assign to servers, VMs, or interfaces.
Subnet mask — 248.0.0.0 is the dotted-decimal equivalent of /5. Older tools and Cisco configs use this format instead of CIDR slash notation.
Full Details
| CIDR Notation | 128.0.0.0/5 |
| Network Address | 128.0.0.0 |
| Broadcast Address | 135.255.255.255 |
| Subnet Mask | 248.0.0.0 |
| Wildcard Mask | 7.255.255.255 |
| Prefix Length | /5 |
| IP Address Class | Class B |
| Total IP Addresses | 134,217,728 |
| Usable Host Addresses | 134,217,726 |
| First Usable IP | 128.0.0.1 |
| Last Usable IP | 135.255.255.254 |
| Network (Hex) | 0x80000000 |
| Broadcast (Hex) | 0x87FFFFFF |
| Address Type | Public / Globally Routable |
Binary Representation
The first 5 bits (1s in the mask) identify the network. The remaining 27 bits identify hosts within the network.
Split into Equal Subnets
Split 128.0.0.0/5 into 2 equal /6 subnets (67,108,862 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 128.0.0.0/6 | 128.0.0.0 | 128.0.0.1 | 131.255.255.254 | 131.255.255.255 | 67,108,862 |
| 2 | 132.0.0.0/6 | 132.0.0.0 | 132.0.0.1 | 135.255.255.254 | 135.255.255.255 | 67,108,862 |
Split 128.0.0.0/5 into 4 equal /7 subnets (33,554,430 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 128.0.0.0/7 | 128.0.0.0 | 128.0.0.1 | 129.255.255.254 | 129.255.255.255 | 33,554,430 |
| 2 | 130.0.0.0/7 | 130.0.0.0 | 130.0.0.1 | 131.255.255.254 | 131.255.255.255 | 33,554,430 |
| 3 | 132.0.0.0/7 | 132.0.0.0 | 132.0.0.1 | 133.255.255.254 | 133.255.255.255 | 33,554,430 |
| 4 | 134.0.0.0/7 | 134.0.0.0 | 134.0.0.1 | 135.255.255.254 | 135.255.255.255 | 33,554,430 |
Split 128.0.0.0/5 into 8 equal /8 subnets (16,777,214 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 128.0.0.0/8 | 128.0.0.0 | 128.0.0.1 | 128.255.255.254 | 128.255.255.255 | 16,777,214 |
| 2 | 129.0.0.0/8 | 129.0.0.0 | 129.0.0.1 | 129.255.255.254 | 129.255.255.255 | 16,777,214 |
| 3 | 130.0.0.0/8 | 130.0.0.0 | 130.0.0.1 | 130.255.255.254 | 130.255.255.255 | 16,777,214 |
| 4 | 131.0.0.0/8 | 131.0.0.0 | 131.0.0.1 | 131.255.255.254 | 131.255.255.255 | 16,777,214 |
| 5 | 132.0.0.0/8 | 132.0.0.0 | 132.0.0.1 | 132.255.255.254 | 132.255.255.255 | 16,777,214 |
| 6 | 133.0.0.0/8 | 133.0.0.0 | 133.0.0.1 | 133.255.255.254 | 133.255.255.255 | 16,777,214 |
| 7 | 134.0.0.0/8 | 134.0.0.0 | 134.0.0.1 | 134.255.255.254 | 134.255.255.255 | 16,777,214 |
| 8 | 135.0.0.0/8 | 135.0.0.0 | 135.0.0.1 | 135.255.255.254 | 135.255.255.255 | 16,777,214 |
Split 128.0.0.0/5 into 16 equal /9 subnets (8,388,606 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 128.0.0.0/9 | 128.0.0.0 | 128.0.0.1 | 128.127.255.254 | 128.127.255.255 | 8,388,606 |
| 2 | 128.128.0.0/9 | 128.128.0.0 | 128.128.0.1 | 128.255.255.254 | 128.255.255.255 | 8,388,606 |
| 3 | 129.0.0.0/9 | 129.0.0.0 | 129.0.0.1 | 129.127.255.254 | 129.127.255.255 | 8,388,606 |
| 4 | 129.128.0.0/9 | 129.128.0.0 | 129.128.0.1 | 129.255.255.254 | 129.255.255.255 | 8,388,606 |
| 5 | 130.0.0.0/9 | 130.0.0.0 | 130.0.0.1 | 130.127.255.254 | 130.127.255.255 | 8,388,606 |
| 6 | 130.128.0.0/9 | 130.128.0.0 | 130.128.0.1 | 130.255.255.254 | 130.255.255.255 | 8,388,606 |
| 7 | 131.0.0.0/9 | 131.0.0.0 | 131.0.0.1 | 131.127.255.254 | 131.127.255.255 | 8,388,606 |
| 8 | 131.128.0.0/9 | 131.128.0.0 | 131.128.0.1 | 131.255.255.254 | 131.255.255.255 | 8,388,606 |
| 9 | 132.0.0.0/9 | 132.0.0.0 | 132.0.0.1 | 132.127.255.254 | 132.127.255.255 | 8,388,606 |
| 10 | 132.128.0.0/9 | 132.128.0.0 | 132.128.0.1 | 132.255.255.254 | 132.255.255.255 | 8,388,606 |
| 11 | 133.0.0.0/9 | 133.0.0.0 | 133.0.0.1 | 133.127.255.254 | 133.127.255.255 | 8,388,606 |
| 12 | 133.128.0.0/9 | 133.128.0.0 | 133.128.0.1 | 133.255.255.254 | 133.255.255.255 | 8,388,606 |
| 13 | 134.0.0.0/9 | 134.0.0.0 | 134.0.0.1 | 134.127.255.254 | 134.127.255.255 | 8,388,606 |
| 14 | 134.128.0.0/9 | 134.128.0.0 | 134.128.0.1 | 134.255.255.254 | 134.255.255.255 | 8,388,606 |
| 15 | 135.0.0.0/9 | 135.0.0.0 | 135.0.0.1 | 135.127.255.254 | 135.127.255.255 | 8,388,606 |
| 16 | 135.128.0.0/9 | 135.128.0.0 | 135.128.0.1 | 135.255.255.254 | 135.255.255.255 | 8,388,606 |