123.131.78.0/23
PublicClass A — /23 prefix — 510 usable hosts
Network address — the base address of the block (123.131.78.0). All devices in this subnet share this prefix. Cannot be assigned to a host.
Broadcast address — packets sent to 123.131.79.255 are delivered to every device in the subnet. Also reserved — not assignable.
Usable hosts — the 510 addresses between those two that you can assign to servers, VMs, or interfaces.
Subnet mask — 255.255.254.0 is the dotted-decimal equivalent of /23. Older tools and Cisco configs use this format instead of CIDR slash notation.
Full Details
| CIDR Notation | 123.131.78.0/23 |
| Network Address | 123.131.78.0 |
| Broadcast Address | 123.131.79.255 |
| Subnet Mask | 255.255.254.0 |
| Wildcard Mask | 0.0.1.255 |
| Prefix Length | /23 |
| IP Address Class | Class A |
| Total IP Addresses | 512 |
| Usable Host Addresses | 510 |
| First Usable IP | 123.131.78.1 |
| Last Usable IP | 123.131.79.254 |
| Network (Hex) | 0x7B834E00 |
| Broadcast (Hex) | 0x7B834FFF |
| Address Type | Public / Globally Routable |
Binary Representation
The first 23 bits (1s in the mask) identify the network. The remaining 9 bits identify hosts within the network.
Split into Equal Subnets
Split 123.131.78.0/23 into 2 equal /24 subnets (254 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 123.131.78.0/24 | 123.131.78.0 | 123.131.78.1 | 123.131.78.254 | 123.131.78.255 | 254 |
| 2 | 123.131.79.0/24 | 123.131.79.0 | 123.131.79.1 | 123.131.79.254 | 123.131.79.255 | 254 |
Split 123.131.78.0/23 into 4 equal /25 subnets (126 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 123.131.78.0/25 | 123.131.78.0 | 123.131.78.1 | 123.131.78.126 | 123.131.78.127 | 126 |
| 2 | 123.131.78.128/25 | 123.131.78.128 | 123.131.78.129 | 123.131.78.254 | 123.131.78.255 | 126 |
| 3 | 123.131.79.0/25 | 123.131.79.0 | 123.131.79.1 | 123.131.79.126 | 123.131.79.127 | 126 |
| 4 | 123.131.79.128/25 | 123.131.79.128 | 123.131.79.129 | 123.131.79.254 | 123.131.79.255 | 126 |
Split 123.131.78.0/23 into 8 equal /26 subnets (62 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 123.131.78.0/26 | 123.131.78.0 | 123.131.78.1 | 123.131.78.62 | 123.131.78.63 | 62 |
| 2 | 123.131.78.64/26 | 123.131.78.64 | 123.131.78.65 | 123.131.78.126 | 123.131.78.127 | 62 |
| 3 | 123.131.78.128/26 | 123.131.78.128 | 123.131.78.129 | 123.131.78.190 | 123.131.78.191 | 62 |
| 4 | 123.131.78.192/26 | 123.131.78.192 | 123.131.78.193 | 123.131.78.254 | 123.131.78.255 | 62 |
| 5 | 123.131.79.0/26 | 123.131.79.0 | 123.131.79.1 | 123.131.79.62 | 123.131.79.63 | 62 |
| 6 | 123.131.79.64/26 | 123.131.79.64 | 123.131.79.65 | 123.131.79.126 | 123.131.79.127 | 62 |
| 7 | 123.131.79.128/26 | 123.131.79.128 | 123.131.79.129 | 123.131.79.190 | 123.131.79.191 | 62 |
| 8 | 123.131.79.192/26 | 123.131.79.192 | 123.131.79.193 | 123.131.79.254 | 123.131.79.255 | 62 |
Split 123.131.78.0/23 into 16 equal /27 subnets (30 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 123.131.78.0/27 | 123.131.78.0 | 123.131.78.1 | 123.131.78.30 | 123.131.78.31 | 30 |
| 2 | 123.131.78.32/27 | 123.131.78.32 | 123.131.78.33 | 123.131.78.62 | 123.131.78.63 | 30 |
| 3 | 123.131.78.64/27 | 123.131.78.64 | 123.131.78.65 | 123.131.78.94 | 123.131.78.95 | 30 |
| 4 | 123.131.78.96/27 | 123.131.78.96 | 123.131.78.97 | 123.131.78.126 | 123.131.78.127 | 30 |
| 5 | 123.131.78.128/27 | 123.131.78.128 | 123.131.78.129 | 123.131.78.158 | 123.131.78.159 | 30 |
| 6 | 123.131.78.160/27 | 123.131.78.160 | 123.131.78.161 | 123.131.78.190 | 123.131.78.191 | 30 |
| 7 | 123.131.78.192/27 | 123.131.78.192 | 123.131.78.193 | 123.131.78.222 | 123.131.78.223 | 30 |
| 8 | 123.131.78.224/27 | 123.131.78.224 | 123.131.78.225 | 123.131.78.254 | 123.131.78.255 | 30 |
| 9 | 123.131.79.0/27 | 123.131.79.0 | 123.131.79.1 | 123.131.79.30 | 123.131.79.31 | 30 |
| 10 | 123.131.79.32/27 | 123.131.79.32 | 123.131.79.33 | 123.131.79.62 | 123.131.79.63 | 30 |
| 11 | 123.131.79.64/27 | 123.131.79.64 | 123.131.79.65 | 123.131.79.94 | 123.131.79.95 | 30 |
| 12 | 123.131.79.96/27 | 123.131.79.96 | 123.131.79.97 | 123.131.79.126 | 123.131.79.127 | 30 |
| 13 | 123.131.79.128/27 | 123.131.79.128 | 123.131.79.129 | 123.131.79.158 | 123.131.79.159 | 30 |
| 14 | 123.131.79.160/27 | 123.131.79.160 | 123.131.79.161 | 123.131.79.190 | 123.131.79.191 | 30 |
| 15 | 123.131.79.192/27 | 123.131.79.192 | 123.131.79.193 | 123.131.79.222 | 123.131.79.223 | 30 |
| 16 | 123.131.79.224/27 | 123.131.79.224 | 123.131.79.225 | 123.131.79.254 | 123.131.79.255 | 30 |