21.252.192.0/18
PublicClass A — /18 prefix — 16,382 usable hosts
Network address — the base address of the block (21.252.192.0). All devices in this subnet share this prefix. Cannot be assigned to a host.
Broadcast address — packets sent to 21.252.255.255 are delivered to every device in the subnet. Also reserved — not assignable.
Usable hosts — the 16,382 addresses between those two that you can assign to servers, VMs, or interfaces.
Subnet mask — 255.255.192.0 is the dotted-decimal equivalent of /18. Older tools and Cisco configs use this format instead of CIDR slash notation.
Full Details
| CIDR Notation | 21.252.192.0/18 |
| Network Address | 21.252.192.0 |
| Broadcast Address | 21.252.255.255 |
| Subnet Mask | 255.255.192.0 |
| Wildcard Mask | 0.0.63.255 |
| Prefix Length | /18 |
| IP Address Class | Class A |
| Total IP Addresses | 16,384 |
| Usable Host Addresses | 16,382 |
| First Usable IP | 21.252.192.1 |
| Last Usable IP | 21.252.255.254 |
| Network (Hex) | 0x15FCC000 |
| Broadcast (Hex) | 0x15FCFFFF |
| Address Type | Public / Globally Routable |
Binary Representation
The first 18 bits (1s in the mask) identify the network. The remaining 14 bits identify hosts within the network.
Split into Equal Subnets
Split 21.252.192.0/18 into 2 equal /19 subnets (8,190 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 21.252.192.0/19 | 21.252.192.0 | 21.252.192.1 | 21.252.223.254 | 21.252.223.255 | 8,190 |
| 2 | 21.252.224.0/19 | 21.252.224.0 | 21.252.224.1 | 21.252.255.254 | 21.252.255.255 | 8,190 |
Split 21.252.192.0/18 into 4 equal /20 subnets (4,094 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 21.252.192.0/20 | 21.252.192.0 | 21.252.192.1 | 21.252.207.254 | 21.252.207.255 | 4,094 |
| 2 | 21.252.208.0/20 | 21.252.208.0 | 21.252.208.1 | 21.252.223.254 | 21.252.223.255 | 4,094 |
| 3 | 21.252.224.0/20 | 21.252.224.0 | 21.252.224.1 | 21.252.239.254 | 21.252.239.255 | 4,094 |
| 4 | 21.252.240.0/20 | 21.252.240.0 | 21.252.240.1 | 21.252.255.254 | 21.252.255.255 | 4,094 |
Split 21.252.192.0/18 into 8 equal /21 subnets (2,046 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 21.252.192.0/21 | 21.252.192.0 | 21.252.192.1 | 21.252.199.254 | 21.252.199.255 | 2,046 |
| 2 | 21.252.200.0/21 | 21.252.200.0 | 21.252.200.1 | 21.252.207.254 | 21.252.207.255 | 2,046 |
| 3 | 21.252.208.0/21 | 21.252.208.0 | 21.252.208.1 | 21.252.215.254 | 21.252.215.255 | 2,046 |
| 4 | 21.252.216.0/21 | 21.252.216.0 | 21.252.216.1 | 21.252.223.254 | 21.252.223.255 | 2,046 |
| 5 | 21.252.224.0/21 | 21.252.224.0 | 21.252.224.1 | 21.252.231.254 | 21.252.231.255 | 2,046 |
| 6 | 21.252.232.0/21 | 21.252.232.0 | 21.252.232.1 | 21.252.239.254 | 21.252.239.255 | 2,046 |
| 7 | 21.252.240.0/21 | 21.252.240.0 | 21.252.240.1 | 21.252.247.254 | 21.252.247.255 | 2,046 |
| 8 | 21.252.248.0/21 | 21.252.248.0 | 21.252.248.1 | 21.252.255.254 | 21.252.255.255 | 2,046 |
Split 21.252.192.0/18 into 16 equal /22 subnets (1,022 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 21.252.192.0/22 | 21.252.192.0 | 21.252.192.1 | 21.252.195.254 | 21.252.195.255 | 1,022 |
| 2 | 21.252.196.0/22 | 21.252.196.0 | 21.252.196.1 | 21.252.199.254 | 21.252.199.255 | 1,022 |
| 3 | 21.252.200.0/22 | 21.252.200.0 | 21.252.200.1 | 21.252.203.254 | 21.252.203.255 | 1,022 |
| 4 | 21.252.204.0/22 | 21.252.204.0 | 21.252.204.1 | 21.252.207.254 | 21.252.207.255 | 1,022 |
| 5 | 21.252.208.0/22 | 21.252.208.0 | 21.252.208.1 | 21.252.211.254 | 21.252.211.255 | 1,022 |
| 6 | 21.252.212.0/22 | 21.252.212.0 | 21.252.212.1 | 21.252.215.254 | 21.252.215.255 | 1,022 |
| 7 | 21.252.216.0/22 | 21.252.216.0 | 21.252.216.1 | 21.252.219.254 | 21.252.219.255 | 1,022 |
| 8 | 21.252.220.0/22 | 21.252.220.0 | 21.252.220.1 | 21.252.223.254 | 21.252.223.255 | 1,022 |
| 9 | 21.252.224.0/22 | 21.252.224.0 | 21.252.224.1 | 21.252.227.254 | 21.252.227.255 | 1,022 |
| 10 | 21.252.228.0/22 | 21.252.228.0 | 21.252.228.1 | 21.252.231.254 | 21.252.231.255 | 1,022 |
| 11 | 21.252.232.0/22 | 21.252.232.0 | 21.252.232.1 | 21.252.235.254 | 21.252.235.255 | 1,022 |
| 12 | 21.252.236.0/22 | 21.252.236.0 | 21.252.236.1 | 21.252.239.254 | 21.252.239.255 | 1,022 |
| 13 | 21.252.240.0/22 | 21.252.240.0 | 21.252.240.1 | 21.252.243.254 | 21.252.243.255 | 1,022 |
| 14 | 21.252.244.0/22 | 21.252.244.0 | 21.252.244.1 | 21.252.247.254 | 21.252.247.255 | 1,022 |
| 15 | 21.252.248.0/22 | 21.252.248.0 | 21.252.248.1 | 21.252.251.254 | 21.252.251.255 | 1,022 |
| 16 | 21.252.252.0/22 | 21.252.252.0 | 21.252.252.1 | 21.252.255.254 | 21.252.255.255 | 1,022 |