138.128.0.0/9
PublicClass B — /9 prefix — 8,388,606 usable hosts
Network address — the base address of the block (138.128.0.0). All devices in this subnet share this prefix. Cannot be assigned to a host.
Broadcast address — packets sent to 138.255.255.255 are delivered to every device in the subnet. Also reserved — not assignable.
Usable hosts — the 8,388,606 addresses between those two that you can assign to servers, VMs, or interfaces.
Subnet mask — 255.128.0.0 is the dotted-decimal equivalent of /9. Older tools and Cisco configs use this format instead of CIDR slash notation.
Full Details
| CIDR Notation | 138.128.0.0/9 |
| Network Address | 138.128.0.0 |
| Broadcast Address | 138.255.255.255 |
| Subnet Mask | 255.128.0.0 |
| Wildcard Mask | 0.127.255.255 |
| Prefix Length | /9 |
| IP Address Class | Class B |
| Total IP Addresses | 8,388,608 |
| Usable Host Addresses | 8,388,606 |
| First Usable IP | 138.128.0.1 |
| Last Usable IP | 138.255.255.254 |
| Network (Hex) | 0x8A800000 |
| Broadcast (Hex) | 0x8AFFFFFF |
| Address Type | Public / Globally Routable |
Binary Representation
The first 9 bits (1s in the mask) identify the network. The remaining 23 bits identify hosts within the network.
Split into Equal Subnets
Split 138.128.0.0/9 into 2 equal /10 subnets (4,194,302 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 138.128.0.0/10 | 138.128.0.0 | 138.128.0.1 | 138.191.255.254 | 138.191.255.255 | 4,194,302 |
| 2 | 138.192.0.0/10 | 138.192.0.0 | 138.192.0.1 | 138.255.255.254 | 138.255.255.255 | 4,194,302 |
Split 138.128.0.0/9 into 4 equal /11 subnets (2,097,150 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 138.128.0.0/11 | 138.128.0.0 | 138.128.0.1 | 138.159.255.254 | 138.159.255.255 | 2,097,150 |
| 2 | 138.160.0.0/11 | 138.160.0.0 | 138.160.0.1 | 138.191.255.254 | 138.191.255.255 | 2,097,150 |
| 3 | 138.192.0.0/11 | 138.192.0.0 | 138.192.0.1 | 138.223.255.254 | 138.223.255.255 | 2,097,150 |
| 4 | 138.224.0.0/11 | 138.224.0.0 | 138.224.0.1 | 138.255.255.254 | 138.255.255.255 | 2,097,150 |
Split 138.128.0.0/9 into 8 equal /12 subnets (1,048,574 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 138.128.0.0/12 | 138.128.0.0 | 138.128.0.1 | 138.143.255.254 | 138.143.255.255 | 1,048,574 |
| 2 | 138.144.0.0/12 | 138.144.0.0 | 138.144.0.1 | 138.159.255.254 | 138.159.255.255 | 1,048,574 |
| 3 | 138.160.0.0/12 | 138.160.0.0 | 138.160.0.1 | 138.175.255.254 | 138.175.255.255 | 1,048,574 |
| 4 | 138.176.0.0/12 | 138.176.0.0 | 138.176.0.1 | 138.191.255.254 | 138.191.255.255 | 1,048,574 |
| 5 | 138.192.0.0/12 | 138.192.0.0 | 138.192.0.1 | 138.207.255.254 | 138.207.255.255 | 1,048,574 |
| 6 | 138.208.0.0/12 | 138.208.0.0 | 138.208.0.1 | 138.223.255.254 | 138.223.255.255 | 1,048,574 |
| 7 | 138.224.0.0/12 | 138.224.0.0 | 138.224.0.1 | 138.239.255.254 | 138.239.255.255 | 1,048,574 |
| 8 | 138.240.0.0/12 | 138.240.0.0 | 138.240.0.1 | 138.255.255.254 | 138.255.255.255 | 1,048,574 |
Split 138.128.0.0/9 into 16 equal /13 subnets (524,286 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 138.128.0.0/13 | 138.128.0.0 | 138.128.0.1 | 138.135.255.254 | 138.135.255.255 | 524,286 |
| 2 | 138.136.0.0/13 | 138.136.0.0 | 138.136.0.1 | 138.143.255.254 | 138.143.255.255 | 524,286 |
| 3 | 138.144.0.0/13 | 138.144.0.0 | 138.144.0.1 | 138.151.255.254 | 138.151.255.255 | 524,286 |
| 4 | 138.152.0.0/13 | 138.152.0.0 | 138.152.0.1 | 138.159.255.254 | 138.159.255.255 | 524,286 |
| 5 | 138.160.0.0/13 | 138.160.0.0 | 138.160.0.1 | 138.167.255.254 | 138.167.255.255 | 524,286 |
| 6 | 138.168.0.0/13 | 138.168.0.0 | 138.168.0.1 | 138.175.255.254 | 138.175.255.255 | 524,286 |
| 7 | 138.176.0.0/13 | 138.176.0.0 | 138.176.0.1 | 138.183.255.254 | 138.183.255.255 | 524,286 |
| 8 | 138.184.0.0/13 | 138.184.0.0 | 138.184.0.1 | 138.191.255.254 | 138.191.255.255 | 524,286 |
| 9 | 138.192.0.0/13 | 138.192.0.0 | 138.192.0.1 | 138.199.255.254 | 138.199.255.255 | 524,286 |
| 10 | 138.200.0.0/13 | 138.200.0.0 | 138.200.0.1 | 138.207.255.254 | 138.207.255.255 | 524,286 |
| 11 | 138.208.0.0/13 | 138.208.0.0 | 138.208.0.1 | 138.215.255.254 | 138.215.255.255 | 524,286 |
| 12 | 138.216.0.0/13 | 138.216.0.0 | 138.216.0.1 | 138.223.255.254 | 138.223.255.255 | 524,286 |
| 13 | 138.224.0.0/13 | 138.224.0.0 | 138.224.0.1 | 138.231.255.254 | 138.231.255.255 | 524,286 |
| 14 | 138.232.0.0/13 | 138.232.0.0 | 138.232.0.1 | 138.239.255.254 | 138.239.255.255 | 524,286 |
| 15 | 138.240.0.0/13 | 138.240.0.0 | 138.240.0.1 | 138.247.255.254 | 138.247.255.255 | 524,286 |
| 16 | 138.248.0.0/13 | 138.248.0.0 | 138.248.0.1 | 138.255.255.254 | 138.255.255.255 | 524,286 |