75.2.64.0/21
PublicClass A — /21 prefix — 2,046 usable hosts
Network address — the base address of the block (75.2.64.0). All devices in this subnet share this prefix. Cannot be assigned to a host.
Broadcast address — packets sent to 75.2.71.255 are delivered to every device in the subnet. Also reserved — not assignable.
Usable hosts — the 2,046 addresses between those two that you can assign to servers, VMs, or interfaces.
Subnet mask — 255.255.248.0 is the dotted-decimal equivalent of /21. Older tools and Cisco configs use this format instead of CIDR slash notation.
Full Details
| CIDR Notation | 75.2.64.0/21 |
| Network Address | 75.2.64.0 |
| Broadcast Address | 75.2.71.255 |
| Subnet Mask | 255.255.248.0 |
| Wildcard Mask | 0.0.7.255 |
| Prefix Length | /21 |
| IP Address Class | Class A |
| Total IP Addresses | 2,048 |
| Usable Host Addresses | 2,046 |
| First Usable IP | 75.2.64.1 |
| Last Usable IP | 75.2.71.254 |
| Network (Hex) | 0x4B024000 |
| Broadcast (Hex) | 0x4B0247FF |
| Address Type | Public / Globally Routable |
Binary Representation
The first 21 bits (1s in the mask) identify the network. The remaining 11 bits identify hosts within the network.
Split into Equal Subnets
Split 75.2.64.0/21 into 2 equal /22 subnets (1,022 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 75.2.64.0/22 | 75.2.64.0 | 75.2.64.1 | 75.2.67.254 | 75.2.67.255 | 1,022 |
| 2 | 75.2.68.0/22 | 75.2.68.0 | 75.2.68.1 | 75.2.71.254 | 75.2.71.255 | 1,022 |
Split 75.2.64.0/21 into 4 equal /23 subnets (510 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 75.2.64.0/23 | 75.2.64.0 | 75.2.64.1 | 75.2.65.254 | 75.2.65.255 | 510 |
| 2 | 75.2.66.0/23 | 75.2.66.0 | 75.2.66.1 | 75.2.67.254 | 75.2.67.255 | 510 |
| 3 | 75.2.68.0/23 | 75.2.68.0 | 75.2.68.1 | 75.2.69.254 | 75.2.69.255 | 510 |
| 4 | 75.2.70.0/23 | 75.2.70.0 | 75.2.70.1 | 75.2.71.254 | 75.2.71.255 | 510 |
Split 75.2.64.0/21 into 8 equal /24 subnets (254 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 75.2.64.0/24 | 75.2.64.0 | 75.2.64.1 | 75.2.64.254 | 75.2.64.255 | 254 |
| 2 | 75.2.65.0/24 | 75.2.65.0 | 75.2.65.1 | 75.2.65.254 | 75.2.65.255 | 254 |
| 3 | 75.2.66.0/24 | 75.2.66.0 | 75.2.66.1 | 75.2.66.254 | 75.2.66.255 | 254 |
| 4 | 75.2.67.0/24 | 75.2.67.0 | 75.2.67.1 | 75.2.67.254 | 75.2.67.255 | 254 |
| 5 | 75.2.68.0/24 | 75.2.68.0 | 75.2.68.1 | 75.2.68.254 | 75.2.68.255 | 254 |
| 6 | 75.2.69.0/24 | 75.2.69.0 | 75.2.69.1 | 75.2.69.254 | 75.2.69.255 | 254 |
| 7 | 75.2.70.0/24 | 75.2.70.0 | 75.2.70.1 | 75.2.70.254 | 75.2.70.255 | 254 |
| 8 | 75.2.71.0/24 | 75.2.71.0 | 75.2.71.1 | 75.2.71.254 | 75.2.71.255 | 254 |
Split 75.2.64.0/21 into 16 equal /25 subnets (126 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 75.2.64.0/25 | 75.2.64.0 | 75.2.64.1 | 75.2.64.126 | 75.2.64.127 | 126 |
| 2 | 75.2.64.128/25 | 75.2.64.128 | 75.2.64.129 | 75.2.64.254 | 75.2.64.255 | 126 |
| 3 | 75.2.65.0/25 | 75.2.65.0 | 75.2.65.1 | 75.2.65.126 | 75.2.65.127 | 126 |
| 4 | 75.2.65.128/25 | 75.2.65.128 | 75.2.65.129 | 75.2.65.254 | 75.2.65.255 | 126 |
| 5 | 75.2.66.0/25 | 75.2.66.0 | 75.2.66.1 | 75.2.66.126 | 75.2.66.127 | 126 |
| 6 | 75.2.66.128/25 | 75.2.66.128 | 75.2.66.129 | 75.2.66.254 | 75.2.66.255 | 126 |
| 7 | 75.2.67.0/25 | 75.2.67.0 | 75.2.67.1 | 75.2.67.126 | 75.2.67.127 | 126 |
| 8 | 75.2.67.128/25 | 75.2.67.128 | 75.2.67.129 | 75.2.67.254 | 75.2.67.255 | 126 |
| 9 | 75.2.68.0/25 | 75.2.68.0 | 75.2.68.1 | 75.2.68.126 | 75.2.68.127 | 126 |
| 10 | 75.2.68.128/25 | 75.2.68.128 | 75.2.68.129 | 75.2.68.254 | 75.2.68.255 | 126 |
| 11 | 75.2.69.0/25 | 75.2.69.0 | 75.2.69.1 | 75.2.69.126 | 75.2.69.127 | 126 |
| 12 | 75.2.69.128/25 | 75.2.69.128 | 75.2.69.129 | 75.2.69.254 | 75.2.69.255 | 126 |
| 13 | 75.2.70.0/25 | 75.2.70.0 | 75.2.70.1 | 75.2.70.126 | 75.2.70.127 | 126 |
| 14 | 75.2.70.128/25 | 75.2.70.128 | 75.2.70.129 | 75.2.70.254 | 75.2.70.255 | 126 |
| 15 | 75.2.71.0/25 | 75.2.71.0 | 75.2.71.1 | 75.2.71.126 | 75.2.71.127 | 126 |
| 16 | 75.2.71.128/25 | 75.2.71.128 | 75.2.71.129 | 75.2.71.254 | 75.2.71.255 | 126 |