0.252.168.0/21
PublicClass A — /21 prefix — 2,046 usable hosts
Network address — the base address of the block (0.252.168.0). All devices in this subnet share this prefix. Cannot be assigned to a host.
Broadcast address — packets sent to 0.252.175.255 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 | 0.252.168.0/21 |
| Network Address | 0.252.168.0 |
| Broadcast Address | 0.252.175.255 |
| 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 | 0.252.168.1 |
| Last Usable IP | 0.252.175.254 |
| Network (Hex) | 0x00FCA800 |
| Broadcast (Hex) | 0x00FCAFFF |
| 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 0.252.168.0/21 into 2 equal /22 subnets (1,022 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 0.252.168.0/22 | 0.252.168.0 | 0.252.168.1 | 0.252.171.254 | 0.252.171.255 | 1,022 |
| 2 | 0.252.172.0/22 | 0.252.172.0 | 0.252.172.1 | 0.252.175.254 | 0.252.175.255 | 1,022 |
Split 0.252.168.0/21 into 4 equal /23 subnets (510 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 0.252.168.0/23 | 0.252.168.0 | 0.252.168.1 | 0.252.169.254 | 0.252.169.255 | 510 |
| 2 | 0.252.170.0/23 | 0.252.170.0 | 0.252.170.1 | 0.252.171.254 | 0.252.171.255 | 510 |
| 3 | 0.252.172.0/23 | 0.252.172.0 | 0.252.172.1 | 0.252.173.254 | 0.252.173.255 | 510 |
| 4 | 0.252.174.0/23 | 0.252.174.0 | 0.252.174.1 | 0.252.175.254 | 0.252.175.255 | 510 |
Split 0.252.168.0/21 into 8 equal /24 subnets (254 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 0.252.168.0/24 | 0.252.168.0 | 0.252.168.1 | 0.252.168.254 | 0.252.168.255 | 254 |
| 2 | 0.252.169.0/24 | 0.252.169.0 | 0.252.169.1 | 0.252.169.254 | 0.252.169.255 | 254 |
| 3 | 0.252.170.0/24 | 0.252.170.0 | 0.252.170.1 | 0.252.170.254 | 0.252.170.255 | 254 |
| 4 | 0.252.171.0/24 | 0.252.171.0 | 0.252.171.1 | 0.252.171.254 | 0.252.171.255 | 254 |
| 5 | 0.252.172.0/24 | 0.252.172.0 | 0.252.172.1 | 0.252.172.254 | 0.252.172.255 | 254 |
| 6 | 0.252.173.0/24 | 0.252.173.0 | 0.252.173.1 | 0.252.173.254 | 0.252.173.255 | 254 |
| 7 | 0.252.174.0/24 | 0.252.174.0 | 0.252.174.1 | 0.252.174.254 | 0.252.174.255 | 254 |
| 8 | 0.252.175.0/24 | 0.252.175.0 | 0.252.175.1 | 0.252.175.254 | 0.252.175.255 | 254 |
Split 0.252.168.0/21 into 16 equal /25 subnets (126 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 0.252.168.0/25 | 0.252.168.0 | 0.252.168.1 | 0.252.168.126 | 0.252.168.127 | 126 |
| 2 | 0.252.168.128/25 | 0.252.168.128 | 0.252.168.129 | 0.252.168.254 | 0.252.168.255 | 126 |
| 3 | 0.252.169.0/25 | 0.252.169.0 | 0.252.169.1 | 0.252.169.126 | 0.252.169.127 | 126 |
| 4 | 0.252.169.128/25 | 0.252.169.128 | 0.252.169.129 | 0.252.169.254 | 0.252.169.255 | 126 |
| 5 | 0.252.170.0/25 | 0.252.170.0 | 0.252.170.1 | 0.252.170.126 | 0.252.170.127 | 126 |
| 6 | 0.252.170.128/25 | 0.252.170.128 | 0.252.170.129 | 0.252.170.254 | 0.252.170.255 | 126 |
| 7 | 0.252.171.0/25 | 0.252.171.0 | 0.252.171.1 | 0.252.171.126 | 0.252.171.127 | 126 |
| 8 | 0.252.171.128/25 | 0.252.171.128 | 0.252.171.129 | 0.252.171.254 | 0.252.171.255 | 126 |
| 9 | 0.252.172.0/25 | 0.252.172.0 | 0.252.172.1 | 0.252.172.126 | 0.252.172.127 | 126 |
| 10 | 0.252.172.128/25 | 0.252.172.128 | 0.252.172.129 | 0.252.172.254 | 0.252.172.255 | 126 |
| 11 | 0.252.173.0/25 | 0.252.173.0 | 0.252.173.1 | 0.252.173.126 | 0.252.173.127 | 126 |
| 12 | 0.252.173.128/25 | 0.252.173.128 | 0.252.173.129 | 0.252.173.254 | 0.252.173.255 | 126 |
| 13 | 0.252.174.0/25 | 0.252.174.0 | 0.252.174.1 | 0.252.174.126 | 0.252.174.127 | 126 |
| 14 | 0.252.174.128/25 | 0.252.174.128 | 0.252.174.129 | 0.252.174.254 | 0.252.174.255 | 126 |
| 15 | 0.252.175.0/25 | 0.252.175.0 | 0.252.175.1 | 0.252.175.126 | 0.252.175.127 | 126 |
| 16 | 0.252.175.128/25 | 0.252.175.128 | 0.252.175.129 | 0.252.175.254 | 0.252.175.255 | 126 |