128.191.0.0/16
PublicClass B — /16 prefix — 65,534 usable hosts
Network address — the base address of the block (128.191.0.0). All devices in this subnet share this prefix. Cannot be assigned to a host.
Broadcast address — packets sent to 128.191.255.255 are delivered to every device in the subnet. Also reserved — not assignable.
Usable hosts — the 65,534 addresses between those two that you can assign to servers, VMs, or interfaces.
Subnet mask — 255.255.0.0 is the dotted-decimal equivalent of /16. Older tools and Cisco configs use this format instead of CIDR slash notation.
Full Details
| CIDR Notation | 128.191.0.0/16 |
| Network Address | 128.191.0.0 |
| Broadcast Address | 128.191.255.255 |
| Subnet Mask | 255.255.0.0 |
| Wildcard Mask | 0.0.255.255 |
| Prefix Length | /16 |
| IP Address Class | Class B |
| Total IP Addresses | 65,536 |
| Usable Host Addresses | 65,534 |
| First Usable IP | 128.191.0.1 |
| Last Usable IP | 128.191.255.254 |
| Network (Hex) | 0x80BF0000 |
| Broadcast (Hex) | 0x80BFFFFF |
| Address Type | Public / Globally Routable |
Binary Representation
The first 16 bits (1s in the mask) identify the network. The remaining 16 bits identify hosts within the network.
Split into Equal Subnets
Split 128.191.0.0/16 into 2 equal /17 subnets (32,766 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 128.191.0.0/17 | 128.191.0.0 | 128.191.0.1 | 128.191.127.254 | 128.191.127.255 | 32,766 |
| 2 | 128.191.128.0/17 | 128.191.128.0 | 128.191.128.1 | 128.191.255.254 | 128.191.255.255 | 32,766 |
Split 128.191.0.0/16 into 4 equal /18 subnets (16,382 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 128.191.0.0/18 | 128.191.0.0 | 128.191.0.1 | 128.191.63.254 | 128.191.63.255 | 16,382 |
| 2 | 128.191.64.0/18 | 128.191.64.0 | 128.191.64.1 | 128.191.127.254 | 128.191.127.255 | 16,382 |
| 3 | 128.191.128.0/18 | 128.191.128.0 | 128.191.128.1 | 128.191.191.254 | 128.191.191.255 | 16,382 |
| 4 | 128.191.192.0/18 | 128.191.192.0 | 128.191.192.1 | 128.191.255.254 | 128.191.255.255 | 16,382 |
Split 128.191.0.0/16 into 8 equal /19 subnets (8,190 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 128.191.0.0/19 | 128.191.0.0 | 128.191.0.1 | 128.191.31.254 | 128.191.31.255 | 8,190 |
| 2 | 128.191.32.0/19 | 128.191.32.0 | 128.191.32.1 | 128.191.63.254 | 128.191.63.255 | 8,190 |
| 3 | 128.191.64.0/19 | 128.191.64.0 | 128.191.64.1 | 128.191.95.254 | 128.191.95.255 | 8,190 |
| 4 | 128.191.96.0/19 | 128.191.96.0 | 128.191.96.1 | 128.191.127.254 | 128.191.127.255 | 8,190 |
| 5 | 128.191.128.0/19 | 128.191.128.0 | 128.191.128.1 | 128.191.159.254 | 128.191.159.255 | 8,190 |
| 6 | 128.191.160.0/19 | 128.191.160.0 | 128.191.160.1 | 128.191.191.254 | 128.191.191.255 | 8,190 |
| 7 | 128.191.192.0/19 | 128.191.192.0 | 128.191.192.1 | 128.191.223.254 | 128.191.223.255 | 8,190 |
| 8 | 128.191.224.0/19 | 128.191.224.0 | 128.191.224.1 | 128.191.255.254 | 128.191.255.255 | 8,190 |
Split 128.191.0.0/16 into 16 equal /20 subnets (4,094 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 128.191.0.0/20 | 128.191.0.0 | 128.191.0.1 | 128.191.15.254 | 128.191.15.255 | 4,094 |
| 2 | 128.191.16.0/20 | 128.191.16.0 | 128.191.16.1 | 128.191.31.254 | 128.191.31.255 | 4,094 |
| 3 | 128.191.32.0/20 | 128.191.32.0 | 128.191.32.1 | 128.191.47.254 | 128.191.47.255 | 4,094 |
| 4 | 128.191.48.0/20 | 128.191.48.0 | 128.191.48.1 | 128.191.63.254 | 128.191.63.255 | 4,094 |
| 5 | 128.191.64.0/20 | 128.191.64.0 | 128.191.64.1 | 128.191.79.254 | 128.191.79.255 | 4,094 |
| 6 | 128.191.80.0/20 | 128.191.80.0 | 128.191.80.1 | 128.191.95.254 | 128.191.95.255 | 4,094 |
| 7 | 128.191.96.0/20 | 128.191.96.0 | 128.191.96.1 | 128.191.111.254 | 128.191.111.255 | 4,094 |
| 8 | 128.191.112.0/20 | 128.191.112.0 | 128.191.112.1 | 128.191.127.254 | 128.191.127.255 | 4,094 |
| 9 | 128.191.128.0/20 | 128.191.128.0 | 128.191.128.1 | 128.191.143.254 | 128.191.143.255 | 4,094 |
| 10 | 128.191.144.0/20 | 128.191.144.0 | 128.191.144.1 | 128.191.159.254 | 128.191.159.255 | 4,094 |
| 11 | 128.191.160.0/20 | 128.191.160.0 | 128.191.160.1 | 128.191.175.254 | 128.191.175.255 | 4,094 |
| 12 | 128.191.176.0/20 | 128.191.176.0 | 128.191.176.1 | 128.191.191.254 | 128.191.191.255 | 4,094 |
| 13 | 128.191.192.0/20 | 128.191.192.0 | 128.191.192.1 | 128.191.207.254 | 128.191.207.255 | 4,094 |
| 14 | 128.191.208.0/20 | 128.191.208.0 | 128.191.208.1 | 128.191.223.254 | 128.191.223.255 | 4,094 |
| 15 | 128.191.224.0/20 | 128.191.224.0 | 128.191.224.1 | 128.191.239.254 | 128.191.239.255 | 4,094 |
| 16 | 128.191.240.0/20 | 128.191.240.0 | 128.191.240.1 | 128.191.255.254 | 128.191.255.255 | 4,094 |