251.64.0.0/11
PublicClass E (Reserved) — /11 prefix — 2,097,150 usable hosts
Network address — the base address of the block (251.64.0.0). All devices in this subnet share this prefix. Cannot be assigned to a host.
Broadcast address — packets sent to 251.95.255.255 are delivered to every device in the subnet. Also reserved — not assignable.
Usable hosts — the 2,097,150 addresses between those two that you can assign to servers, VMs, or interfaces.
Subnet mask — 255.224.0.0 is the dotted-decimal equivalent of /11. Older tools and Cisco configs use this format instead of CIDR slash notation.
Full Details
| CIDR Notation | 251.64.0.0/11 |
| Network Address | 251.64.0.0 |
| Broadcast Address | 251.95.255.255 |
| Subnet Mask | 255.224.0.0 |
| Wildcard Mask | 0.31.255.255 |
| Prefix Length | /11 |
| IP Address Class | Class E (Reserved) |
| Total IP Addresses | 2,097,152 |
| Usable Host Addresses | 2,097,150 |
| First Usable IP | 251.64.0.1 |
| Last Usable IP | 251.95.255.254 |
| Network (Hex) | 0xFB400000 |
| Broadcast (Hex) | 0xFB5FFFFF |
| Address Type | Public / Globally Routable |
Binary Representation
The first 11 bits (1s in the mask) identify the network. The remaining 21 bits identify hosts within the network.
Split into Equal Subnets
Split 251.64.0.0/11 into 2 equal /12 subnets (1,048,574 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 251.64.0.0/12 | 251.64.0.0 | 251.64.0.1 | 251.79.255.254 | 251.79.255.255 | 1,048,574 |
| 2 | 251.80.0.0/12 | 251.80.0.0 | 251.80.0.1 | 251.95.255.254 | 251.95.255.255 | 1,048,574 |
Split 251.64.0.0/11 into 4 equal /13 subnets (524,286 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 251.64.0.0/13 | 251.64.0.0 | 251.64.0.1 | 251.71.255.254 | 251.71.255.255 | 524,286 |
| 2 | 251.72.0.0/13 | 251.72.0.0 | 251.72.0.1 | 251.79.255.254 | 251.79.255.255 | 524,286 |
| 3 | 251.80.0.0/13 | 251.80.0.0 | 251.80.0.1 | 251.87.255.254 | 251.87.255.255 | 524,286 |
| 4 | 251.88.0.0/13 | 251.88.0.0 | 251.88.0.1 | 251.95.255.254 | 251.95.255.255 | 524,286 |
Split 251.64.0.0/11 into 8 equal /14 subnets (262,142 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 251.64.0.0/14 | 251.64.0.0 | 251.64.0.1 | 251.67.255.254 | 251.67.255.255 | 262,142 |
| 2 | 251.68.0.0/14 | 251.68.0.0 | 251.68.0.1 | 251.71.255.254 | 251.71.255.255 | 262,142 |
| 3 | 251.72.0.0/14 | 251.72.0.0 | 251.72.0.1 | 251.75.255.254 | 251.75.255.255 | 262,142 |
| 4 | 251.76.0.0/14 | 251.76.0.0 | 251.76.0.1 | 251.79.255.254 | 251.79.255.255 | 262,142 |
| 5 | 251.80.0.0/14 | 251.80.0.0 | 251.80.0.1 | 251.83.255.254 | 251.83.255.255 | 262,142 |
| 6 | 251.84.0.0/14 | 251.84.0.0 | 251.84.0.1 | 251.87.255.254 | 251.87.255.255 | 262,142 |
| 7 | 251.88.0.0/14 | 251.88.0.0 | 251.88.0.1 | 251.91.255.254 | 251.91.255.255 | 262,142 |
| 8 | 251.92.0.0/14 | 251.92.0.0 | 251.92.0.1 | 251.95.255.254 | 251.95.255.255 | 262,142 |
Split 251.64.0.0/11 into 16 equal /15 subnets (131,070 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 251.64.0.0/15 | 251.64.0.0 | 251.64.0.1 | 251.65.255.254 | 251.65.255.255 | 131,070 |
| 2 | 251.66.0.0/15 | 251.66.0.0 | 251.66.0.1 | 251.67.255.254 | 251.67.255.255 | 131,070 |
| 3 | 251.68.0.0/15 | 251.68.0.0 | 251.68.0.1 | 251.69.255.254 | 251.69.255.255 | 131,070 |
| 4 | 251.70.0.0/15 | 251.70.0.0 | 251.70.0.1 | 251.71.255.254 | 251.71.255.255 | 131,070 |
| 5 | 251.72.0.0/15 | 251.72.0.0 | 251.72.0.1 | 251.73.255.254 | 251.73.255.255 | 131,070 |
| 6 | 251.74.0.0/15 | 251.74.0.0 | 251.74.0.1 | 251.75.255.254 | 251.75.255.255 | 131,070 |
| 7 | 251.76.0.0/15 | 251.76.0.0 | 251.76.0.1 | 251.77.255.254 | 251.77.255.255 | 131,070 |
| 8 | 251.78.0.0/15 | 251.78.0.0 | 251.78.0.1 | 251.79.255.254 | 251.79.255.255 | 131,070 |
| 9 | 251.80.0.0/15 | 251.80.0.0 | 251.80.0.1 | 251.81.255.254 | 251.81.255.255 | 131,070 |
| 10 | 251.82.0.0/15 | 251.82.0.0 | 251.82.0.1 | 251.83.255.254 | 251.83.255.255 | 131,070 |
| 11 | 251.84.0.0/15 | 251.84.0.0 | 251.84.0.1 | 251.85.255.254 | 251.85.255.255 | 131,070 |
| 12 | 251.86.0.0/15 | 251.86.0.0 | 251.86.0.1 | 251.87.255.254 | 251.87.255.255 | 131,070 |
| 13 | 251.88.0.0/15 | 251.88.0.0 | 251.88.0.1 | 251.89.255.254 | 251.89.255.255 | 131,070 |
| 14 | 251.90.0.0/15 | 251.90.0.0 | 251.90.0.1 | 251.91.255.254 | 251.91.255.255 | 131,070 |
| 15 | 251.92.0.0/15 | 251.92.0.0 | 251.92.0.1 | 251.93.255.254 | 251.93.255.255 | 131,070 |
| 16 | 251.94.0.0/15 | 251.94.0.0 | 251.94.0.1 | 251.95.255.254 | 251.95.255.255 | 131,070 |