203.0.113.0/24
Public RFC 5737203.0.113.0/24 (TEST-NET-3) is the third documentation range from RFC 5737, suitable for use in examples, diagrams, and documentation where a routable-looking IP is needed.
Network address — the base address of the block (203.0.113.0). All devices in this subnet share this prefix. Cannot be assigned to a host.
Broadcast address — packets sent to 203.0.113.255 are delivered to every device in the subnet. Also reserved — not assignable.
Usable hosts — the 254 addresses between those two that you can assign to servers, VMs, or interfaces.
Subnet mask — 255.255.255.0 is the dotted-decimal equivalent of /24. Older tools and Cisco configs use this format instead of CIDR slash notation.
Full Details
| CIDR Notation | 203.0.113.0/24 |
| Network Address | 203.0.113.0 |
| Broadcast Address | 203.0.113.255 |
| Subnet Mask | 255.255.255.0 |
| Wildcard Mask | 0.0.0.255 |
| Prefix Length | /24 |
| IP Address Class | Class C |
| Total IP Addresses | 256 |
| Usable Host Addresses | 254 |
| First Usable IP | 203.0.113.1 |
| Last Usable IP | 203.0.113.254 |
| Network (Hex) | 0xCB007100 |
| Broadcast (Hex) | 0xCB0071FF |
| Governing RFC | RFC 5737 |
| Address Type | Public / Globally Routable |
Binary Representation
The first 24 bits (1s in the mask) identify the network. The remaining 8 bits identify hosts within the network.
Subnet Breakdown — splitting into /25
This /24 block can be divided into 2 /25 subnets.
| CIDR | Network | Broadcast | First Usable | Last Usable | Hosts |
|---|---|---|---|---|---|
| 203.0.113.0/25 | 203.0.113.0 | 203.0.113.127 | 203.0.113.1 | 203.0.113.126 | 126 |
| 203.0.113.128/25 | 203.0.113.128 | 203.0.113.255 | 203.0.113.129 | 203.0.113.254 | 126 |
IP Address Sample
Showing first 16 of 256 total IPs.
Common Use Cases
- → Documentation and examples
- → Network diagrams
- → Training materials