10.245.152.0/21
Private (RFC 1918) RFC 1918Class A — /21 prefix — 2,046 usable hosts
Network address — the base address of the block (10.245.152.0). All devices in this subnet share this prefix. Cannot be assigned to a host.
Broadcast address — packets sent to 10.245.159.255 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 | 10.245.152.0/21 |
| Network Address | 10.245.152.0 |
| Broadcast Address | 10.245.159.255 |
| 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 | 10.245.152.1 |
| Last Usable IP | 10.245.159.254 |
| Network (Hex) | 0x0AF59800 |
| Broadcast (Hex) | 0x0AF59FFF |
| Governing RFC | RFC 1918 |
| Address Type | Private (RFC 1918) |
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 10.245.152.0/21 into 2 equal /22 subnets (1,022 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 10.245.152.0/22 | 10.245.152.0 | 10.245.152.1 | 10.245.155.254 | 10.245.155.255 | 1,022 |
| 2 | 10.245.156.0/22 | 10.245.156.0 | 10.245.156.1 | 10.245.159.254 | 10.245.159.255 | 1,022 |
Split 10.245.152.0/21 into 4 equal /23 subnets (510 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 10.245.152.0/23 | 10.245.152.0 | 10.245.152.1 | 10.245.153.254 | 10.245.153.255 | 510 |
| 2 | 10.245.154.0/23 | 10.245.154.0 | 10.245.154.1 | 10.245.155.254 | 10.245.155.255 | 510 |
| 3 | 10.245.156.0/23 | 10.245.156.0 | 10.245.156.1 | 10.245.157.254 | 10.245.157.255 | 510 |
| 4 | 10.245.158.0/23 | 10.245.158.0 | 10.245.158.1 | 10.245.159.254 | 10.245.159.255 | 510 |
Split 10.245.152.0/21 into 8 equal /24 subnets (254 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 10.245.152.0/24 | 10.245.152.0 | 10.245.152.1 | 10.245.152.254 | 10.245.152.255 | 254 |
| 2 | 10.245.153.0/24 | 10.245.153.0 | 10.245.153.1 | 10.245.153.254 | 10.245.153.255 | 254 |
| 3 | 10.245.154.0/24 | 10.245.154.0 | 10.245.154.1 | 10.245.154.254 | 10.245.154.255 | 254 |
| 4 | 10.245.155.0/24 | 10.245.155.0 | 10.245.155.1 | 10.245.155.254 | 10.245.155.255 | 254 |
| 5 | 10.245.156.0/24 | 10.245.156.0 | 10.245.156.1 | 10.245.156.254 | 10.245.156.255 | 254 |
| 6 | 10.245.157.0/24 | 10.245.157.0 | 10.245.157.1 | 10.245.157.254 | 10.245.157.255 | 254 |
| 7 | 10.245.158.0/24 | 10.245.158.0 | 10.245.158.1 | 10.245.158.254 | 10.245.158.255 | 254 |
| 8 | 10.245.159.0/24 | 10.245.159.0 | 10.245.159.1 | 10.245.159.254 | 10.245.159.255 | 254 |
Split 10.245.152.0/21 into 16 equal /25 subnets (126 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 10.245.152.0/25 | 10.245.152.0 | 10.245.152.1 | 10.245.152.126 | 10.245.152.127 | 126 |
| 2 | 10.245.152.128/25 | 10.245.152.128 | 10.245.152.129 | 10.245.152.254 | 10.245.152.255 | 126 |
| 3 | 10.245.153.0/25 | 10.245.153.0 | 10.245.153.1 | 10.245.153.126 | 10.245.153.127 | 126 |
| 4 | 10.245.153.128/25 | 10.245.153.128 | 10.245.153.129 | 10.245.153.254 | 10.245.153.255 | 126 |
| 5 | 10.245.154.0/25 | 10.245.154.0 | 10.245.154.1 | 10.245.154.126 | 10.245.154.127 | 126 |
| 6 | 10.245.154.128/25 | 10.245.154.128 | 10.245.154.129 | 10.245.154.254 | 10.245.154.255 | 126 |
| 7 | 10.245.155.0/25 | 10.245.155.0 | 10.245.155.1 | 10.245.155.126 | 10.245.155.127 | 126 |
| 8 | 10.245.155.128/25 | 10.245.155.128 | 10.245.155.129 | 10.245.155.254 | 10.245.155.255 | 126 |
| 9 | 10.245.156.0/25 | 10.245.156.0 | 10.245.156.1 | 10.245.156.126 | 10.245.156.127 | 126 |
| 10 | 10.245.156.128/25 | 10.245.156.128 | 10.245.156.129 | 10.245.156.254 | 10.245.156.255 | 126 |
| 11 | 10.245.157.0/25 | 10.245.157.0 | 10.245.157.1 | 10.245.157.126 | 10.245.157.127 | 126 |
| 12 | 10.245.157.128/25 | 10.245.157.128 | 10.245.157.129 | 10.245.157.254 | 10.245.157.255 | 126 |
| 13 | 10.245.158.0/25 | 10.245.158.0 | 10.245.158.1 | 10.245.158.126 | 10.245.158.127 | 126 |
| 14 | 10.245.158.128/25 | 10.245.158.128 | 10.245.158.129 | 10.245.158.254 | 10.245.158.255 | 126 |
| 15 | 10.245.159.0/25 | 10.245.159.0 | 10.245.159.1 | 10.245.159.126 | 10.245.159.127 | 126 |
| 16 | 10.245.159.128/25 | 10.245.159.128 | 10.245.159.129 | 10.245.159.254 | 10.245.159.255 | 126 |