1.100.0.0/15
PublicClass A — /15 prefix — 131,070 usable hosts
Network address — the base address of the block (1.100.0.0). All devices in this subnet share this prefix. Cannot be assigned to a host.
Broadcast address — packets sent to 1.101.255.255 are delivered to every device in the subnet. Also reserved — not assignable.
Usable hosts — the 131,070 addresses between those two that you can assign to servers, VMs, or interfaces.
Subnet mask — 255.254.0.0 is the dotted-decimal equivalent of /15. Older tools and Cisco configs use this format instead of CIDR slash notation.
Full Details
| CIDR Notation | 1.100.0.0/15 |
| Network Address | 1.100.0.0 |
| Broadcast Address | 1.101.255.255 |
| Subnet Mask | 255.254.0.0 |
| Wildcard Mask | 0.1.255.255 |
| Prefix Length | /15 |
| IP Address Class | Class A |
| Total IP Addresses | 131,072 |
| Usable Host Addresses | 131,070 |
| First Usable IP | 1.100.0.1 |
| Last Usable IP | 1.101.255.254 |
| Network (Hex) | 0x01640000 |
| Broadcast (Hex) | 0x0165FFFF |
| Address Type | Public / Globally Routable |
Binary Representation
The first 15 bits (1s in the mask) identify the network. The remaining 17 bits identify hosts within the network.
Split into Equal Subnets
Split 1.100.0.0/15 into 2 equal /16 subnets (65,534 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 1.100.0.0/16 | 1.100.0.0 | 1.100.0.1 | 1.100.255.254 | 1.100.255.255 | 65,534 |
| 2 | 1.101.0.0/16 | 1.101.0.0 | 1.101.0.1 | 1.101.255.254 | 1.101.255.255 | 65,534 |
Split 1.100.0.0/15 into 4 equal /17 subnets (32,766 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 1.100.0.0/17 | 1.100.0.0 | 1.100.0.1 | 1.100.127.254 | 1.100.127.255 | 32,766 |
| 2 | 1.100.128.0/17 | 1.100.128.0 | 1.100.128.1 | 1.100.255.254 | 1.100.255.255 | 32,766 |
| 3 | 1.101.0.0/17 | 1.101.0.0 | 1.101.0.1 | 1.101.127.254 | 1.101.127.255 | 32,766 |
| 4 | 1.101.128.0/17 | 1.101.128.0 | 1.101.128.1 | 1.101.255.254 | 1.101.255.255 | 32,766 |
Split 1.100.0.0/15 into 8 equal /18 subnets (16,382 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 1.100.0.0/18 | 1.100.0.0 | 1.100.0.1 | 1.100.63.254 | 1.100.63.255 | 16,382 |
| 2 | 1.100.64.0/18 | 1.100.64.0 | 1.100.64.1 | 1.100.127.254 | 1.100.127.255 | 16,382 |
| 3 | 1.100.128.0/18 | 1.100.128.0 | 1.100.128.1 | 1.100.191.254 | 1.100.191.255 | 16,382 |
| 4 | 1.100.192.0/18 | 1.100.192.0 | 1.100.192.1 | 1.100.255.254 | 1.100.255.255 | 16,382 |
| 5 | 1.101.0.0/18 | 1.101.0.0 | 1.101.0.1 | 1.101.63.254 | 1.101.63.255 | 16,382 |
| 6 | 1.101.64.0/18 | 1.101.64.0 | 1.101.64.1 | 1.101.127.254 | 1.101.127.255 | 16,382 |
| 7 | 1.101.128.0/18 | 1.101.128.0 | 1.101.128.1 | 1.101.191.254 | 1.101.191.255 | 16,382 |
| 8 | 1.101.192.0/18 | 1.101.192.0 | 1.101.192.1 | 1.101.255.254 | 1.101.255.255 | 16,382 |
Split 1.100.0.0/15 into 16 equal /19 subnets (8,190 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 1.100.0.0/19 | 1.100.0.0 | 1.100.0.1 | 1.100.31.254 | 1.100.31.255 | 8,190 |
| 2 | 1.100.32.0/19 | 1.100.32.0 | 1.100.32.1 | 1.100.63.254 | 1.100.63.255 | 8,190 |
| 3 | 1.100.64.0/19 | 1.100.64.0 | 1.100.64.1 | 1.100.95.254 | 1.100.95.255 | 8,190 |
| 4 | 1.100.96.0/19 | 1.100.96.0 | 1.100.96.1 | 1.100.127.254 | 1.100.127.255 | 8,190 |
| 5 | 1.100.128.0/19 | 1.100.128.0 | 1.100.128.1 | 1.100.159.254 | 1.100.159.255 | 8,190 |
| 6 | 1.100.160.0/19 | 1.100.160.0 | 1.100.160.1 | 1.100.191.254 | 1.100.191.255 | 8,190 |
| 7 | 1.100.192.0/19 | 1.100.192.0 | 1.100.192.1 | 1.100.223.254 | 1.100.223.255 | 8,190 |
| 8 | 1.100.224.0/19 | 1.100.224.0 | 1.100.224.1 | 1.100.255.254 | 1.100.255.255 | 8,190 |
| 9 | 1.101.0.0/19 | 1.101.0.0 | 1.101.0.1 | 1.101.31.254 | 1.101.31.255 | 8,190 |
| 10 | 1.101.32.0/19 | 1.101.32.0 | 1.101.32.1 | 1.101.63.254 | 1.101.63.255 | 8,190 |
| 11 | 1.101.64.0/19 | 1.101.64.0 | 1.101.64.1 | 1.101.95.254 | 1.101.95.255 | 8,190 |
| 12 | 1.101.96.0/19 | 1.101.96.0 | 1.101.96.1 | 1.101.127.254 | 1.101.127.255 | 8,190 |
| 13 | 1.101.128.0/19 | 1.101.128.0 | 1.101.128.1 | 1.101.159.254 | 1.101.159.255 | 8,190 |
| 14 | 1.101.160.0/19 | 1.101.160.0 | 1.101.160.1 | 1.101.191.254 | 1.101.191.255 | 8,190 |
| 15 | 1.101.192.0/19 | 1.101.192.0 | 1.101.192.1 | 1.101.223.254 | 1.101.223.255 | 8,190 |
| 16 | 1.101.224.0/19 | 1.101.224.0 | 1.101.224.1 | 1.101.255.254 | 1.101.255.255 | 8,190 |