10.178.192.0/21
Private (RFC 1918) RFC 1918Class A — /21 prefix — 2,046 usable hosts
Network address — the base address of the block (10.178.192.0). All devices in this subnet share this prefix. Cannot be assigned to a host.
Broadcast address — packets sent to 10.178.199.255 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 | 10.178.192.0/21 |
| Network Address | 10.178.192.0 |
| Broadcast Address | 10.178.199.255 |
| 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 | 10.178.192.1 |
| Last Usable IP | 10.178.199.254 |
| Network (Hex) | 0x0AB2C000 |
| Broadcast (Hex) | 0x0AB2C7FF |
| 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 10.178.192.0/21 into 2 equal /22 subnets (1,022 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 10.178.192.0/22 | 10.178.192.0 | 10.178.192.1 | 10.178.195.254 | 10.178.195.255 | 1,022 |
| 2 | 10.178.196.0/22 | 10.178.196.0 | 10.178.196.1 | 10.178.199.254 | 10.178.199.255 | 1,022 |
Split 10.178.192.0/21 into 4 equal /23 subnets (510 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 10.178.192.0/23 | 10.178.192.0 | 10.178.192.1 | 10.178.193.254 | 10.178.193.255 | 510 |
| 2 | 10.178.194.0/23 | 10.178.194.0 | 10.178.194.1 | 10.178.195.254 | 10.178.195.255 | 510 |
| 3 | 10.178.196.0/23 | 10.178.196.0 | 10.178.196.1 | 10.178.197.254 | 10.178.197.255 | 510 |
| 4 | 10.178.198.0/23 | 10.178.198.0 | 10.178.198.1 | 10.178.199.254 | 10.178.199.255 | 510 |
Split 10.178.192.0/21 into 8 equal /24 subnets (254 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 10.178.192.0/24 | 10.178.192.0 | 10.178.192.1 | 10.178.192.254 | 10.178.192.255 | 254 |
| 2 | 10.178.193.0/24 | 10.178.193.0 | 10.178.193.1 | 10.178.193.254 | 10.178.193.255 | 254 |
| 3 | 10.178.194.0/24 | 10.178.194.0 | 10.178.194.1 | 10.178.194.254 | 10.178.194.255 | 254 |
| 4 | 10.178.195.0/24 | 10.178.195.0 | 10.178.195.1 | 10.178.195.254 | 10.178.195.255 | 254 |
| 5 | 10.178.196.0/24 | 10.178.196.0 | 10.178.196.1 | 10.178.196.254 | 10.178.196.255 | 254 |
| 6 | 10.178.197.0/24 | 10.178.197.0 | 10.178.197.1 | 10.178.197.254 | 10.178.197.255 | 254 |
| 7 | 10.178.198.0/24 | 10.178.198.0 | 10.178.198.1 | 10.178.198.254 | 10.178.198.255 | 254 |
| 8 | 10.178.199.0/24 | 10.178.199.0 | 10.178.199.1 | 10.178.199.254 | 10.178.199.255 | 254 |
Split 10.178.192.0/21 into 16 equal /25 subnets (126 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 10.178.192.0/25 | 10.178.192.0 | 10.178.192.1 | 10.178.192.126 | 10.178.192.127 | 126 |
| 2 | 10.178.192.128/25 | 10.178.192.128 | 10.178.192.129 | 10.178.192.254 | 10.178.192.255 | 126 |
| 3 | 10.178.193.0/25 | 10.178.193.0 | 10.178.193.1 | 10.178.193.126 | 10.178.193.127 | 126 |
| 4 | 10.178.193.128/25 | 10.178.193.128 | 10.178.193.129 | 10.178.193.254 | 10.178.193.255 | 126 |
| 5 | 10.178.194.0/25 | 10.178.194.0 | 10.178.194.1 | 10.178.194.126 | 10.178.194.127 | 126 |
| 6 | 10.178.194.128/25 | 10.178.194.128 | 10.178.194.129 | 10.178.194.254 | 10.178.194.255 | 126 |
| 7 | 10.178.195.0/25 | 10.178.195.0 | 10.178.195.1 | 10.178.195.126 | 10.178.195.127 | 126 |
| 8 | 10.178.195.128/25 | 10.178.195.128 | 10.178.195.129 | 10.178.195.254 | 10.178.195.255 | 126 |
| 9 | 10.178.196.0/25 | 10.178.196.0 | 10.178.196.1 | 10.178.196.126 | 10.178.196.127 | 126 |
| 10 | 10.178.196.128/25 | 10.178.196.128 | 10.178.196.129 | 10.178.196.254 | 10.178.196.255 | 126 |
| 11 | 10.178.197.0/25 | 10.178.197.0 | 10.178.197.1 | 10.178.197.126 | 10.178.197.127 | 126 |
| 12 | 10.178.197.128/25 | 10.178.197.128 | 10.178.197.129 | 10.178.197.254 | 10.178.197.255 | 126 |
| 13 | 10.178.198.0/25 | 10.178.198.0 | 10.178.198.1 | 10.178.198.126 | 10.178.198.127 | 126 |
| 14 | 10.178.198.128/25 | 10.178.198.128 | 10.178.198.129 | 10.178.198.254 | 10.178.198.255 | 126 |
| 15 | 10.178.199.0/25 | 10.178.199.0 | 10.178.199.1 | 10.178.199.126 | 10.178.199.127 | 126 |
| 16 | 10.178.199.128/25 | 10.178.199.128 | 10.178.199.129 | 10.178.199.254 | 10.178.199.255 | 126 |