12.16.0.0/16
PublicClass A — /16 prefix — 65,534 usable hosts
Network address — the base address of the block (12.16.0.0). All devices in this subnet share this prefix. Cannot be assigned to a host.
Broadcast address — packets sent to 12.16.255.255 are delivered to every device in the subnet. Also reserved — not assignable.
Usable hosts — the 65,534 addresses between those two that you can assign to servers, VMs, or interfaces.
Subnet mask — 255.255.0.0 is the dotted-decimal equivalent of /16. Older tools and Cisco configs use this format instead of CIDR slash notation.
Full Details
| CIDR Notation | 12.16.0.0/16 |
| Network Address | 12.16.0.0 |
| Broadcast Address | 12.16.255.255 |
| Subnet Mask | 255.255.0.0 |
| Wildcard Mask | 0.0.255.255 |
| Prefix Length | /16 |
| IP Address Class | Class A |
| Total IP Addresses | 65,536 |
| Usable Host Addresses | 65,534 |
| First Usable IP | 12.16.0.1 |
| Last Usable IP | 12.16.255.254 |
| Network (Hex) | 0x0C100000 |
| Broadcast (Hex) | 0x0C10FFFF |
| Address Type | Public / Globally Routable |
Binary Representation
The first 16 bits (1s in the mask) identify the network. The remaining 16 bits identify hosts within the network.
Subnet Breakdown — splitting into /17
This /16 block can be divided into 2 /17 subnets.
| CIDR | Network | Broadcast | First Usable | Last Usable | Hosts |
|---|---|---|---|---|---|
| 12.16.0.0/17 | 12.16.0.0 | 12.16.127.255 | 12.16.0.1 | 12.16.127.254 | 32,766 |
| 12.16.128.0/17 | 12.16.128.0 | 12.16.255.255 | 12.16.128.1 | 12.16.255.254 | 32,766 |