31.205.128.0/17
PublicClass A — /17 prefix — 32,766 usable hosts
Network address — the base address of the block (31.205.128.0). All devices in this subnet share this prefix. Cannot be assigned to a host.
Broadcast address — packets sent to 31.205.255.255 are delivered to every device in the subnet. Also reserved — not assignable.
Usable hosts — the 32,766 addresses between those two that you can assign to servers, VMs, or interfaces.
Subnet mask — 255.255.128.0 is the dotted-decimal equivalent of /17. Older tools and Cisco configs use this format instead of CIDR slash notation.
Full Details
| CIDR Notation | 31.205.128.0/17 |
| Network Address | 31.205.128.0 |
| Broadcast Address | 31.205.255.255 |
| Subnet Mask | 255.255.128.0 |
| Wildcard Mask | 0.0.127.255 |
| Prefix Length | /17 |
| IP Address Class | Class A |
| Total IP Addresses | 32,768 |
| Usable Host Addresses | 32,766 |
| First Usable IP | 31.205.128.1 |
| Last Usable IP | 31.205.255.254 |
| Network (Hex) | 0x1FCD8000 |
| Broadcast (Hex) | 0x1FCDFFFF |
| Address Type | Public / Globally Routable |
Binary Representation
The first 17 bits (1s in the mask) identify the network. The remaining 15 bits identify hosts within the network.
Split into Equal Subnets
Split 31.205.128.0/17 into 2 equal /18 subnets (16,382 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 31.205.128.0/18 | 31.205.128.0 | 31.205.128.1 | 31.205.191.254 | 31.205.191.255 | 16,382 |
| 2 | 31.205.192.0/18 | 31.205.192.0 | 31.205.192.1 | 31.205.255.254 | 31.205.255.255 | 16,382 |
Split 31.205.128.0/17 into 4 equal /19 subnets (8,190 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 31.205.128.0/19 | 31.205.128.0 | 31.205.128.1 | 31.205.159.254 | 31.205.159.255 | 8,190 |
| 2 | 31.205.160.0/19 | 31.205.160.0 | 31.205.160.1 | 31.205.191.254 | 31.205.191.255 | 8,190 |
| 3 | 31.205.192.0/19 | 31.205.192.0 | 31.205.192.1 | 31.205.223.254 | 31.205.223.255 | 8,190 |
| 4 | 31.205.224.0/19 | 31.205.224.0 | 31.205.224.1 | 31.205.255.254 | 31.205.255.255 | 8,190 |
Split 31.205.128.0/17 into 8 equal /20 subnets (4,094 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 31.205.128.0/20 | 31.205.128.0 | 31.205.128.1 | 31.205.143.254 | 31.205.143.255 | 4,094 |
| 2 | 31.205.144.0/20 | 31.205.144.0 | 31.205.144.1 | 31.205.159.254 | 31.205.159.255 | 4,094 |
| 3 | 31.205.160.0/20 | 31.205.160.0 | 31.205.160.1 | 31.205.175.254 | 31.205.175.255 | 4,094 |
| 4 | 31.205.176.0/20 | 31.205.176.0 | 31.205.176.1 | 31.205.191.254 | 31.205.191.255 | 4,094 |
| 5 | 31.205.192.0/20 | 31.205.192.0 | 31.205.192.1 | 31.205.207.254 | 31.205.207.255 | 4,094 |
| 6 | 31.205.208.0/20 | 31.205.208.0 | 31.205.208.1 | 31.205.223.254 | 31.205.223.255 | 4,094 |
| 7 | 31.205.224.0/20 | 31.205.224.0 | 31.205.224.1 | 31.205.239.254 | 31.205.239.255 | 4,094 |
| 8 | 31.205.240.0/20 | 31.205.240.0 | 31.205.240.1 | 31.205.255.254 | 31.205.255.255 | 4,094 |
Split 31.205.128.0/17 into 16 equal /21 subnets (2,046 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 31.205.128.0/21 | 31.205.128.0 | 31.205.128.1 | 31.205.135.254 | 31.205.135.255 | 2,046 |
| 2 | 31.205.136.0/21 | 31.205.136.0 | 31.205.136.1 | 31.205.143.254 | 31.205.143.255 | 2,046 |
| 3 | 31.205.144.0/21 | 31.205.144.0 | 31.205.144.1 | 31.205.151.254 | 31.205.151.255 | 2,046 |
| 4 | 31.205.152.0/21 | 31.205.152.0 | 31.205.152.1 | 31.205.159.254 | 31.205.159.255 | 2,046 |
| 5 | 31.205.160.0/21 | 31.205.160.0 | 31.205.160.1 | 31.205.167.254 | 31.205.167.255 | 2,046 |
| 6 | 31.205.168.0/21 | 31.205.168.0 | 31.205.168.1 | 31.205.175.254 | 31.205.175.255 | 2,046 |
| 7 | 31.205.176.0/21 | 31.205.176.0 | 31.205.176.1 | 31.205.183.254 | 31.205.183.255 | 2,046 |
| 8 | 31.205.184.0/21 | 31.205.184.0 | 31.205.184.1 | 31.205.191.254 | 31.205.191.255 | 2,046 |
| 9 | 31.205.192.0/21 | 31.205.192.0 | 31.205.192.1 | 31.205.199.254 | 31.205.199.255 | 2,046 |
| 10 | 31.205.200.0/21 | 31.205.200.0 | 31.205.200.1 | 31.205.207.254 | 31.205.207.255 | 2,046 |
| 11 | 31.205.208.0/21 | 31.205.208.0 | 31.205.208.1 | 31.205.215.254 | 31.205.215.255 | 2,046 |
| 12 | 31.205.216.0/21 | 31.205.216.0 | 31.205.216.1 | 31.205.223.254 | 31.205.223.255 | 2,046 |
| 13 | 31.205.224.0/21 | 31.205.224.0 | 31.205.224.1 | 31.205.231.254 | 31.205.231.255 | 2,046 |
| 14 | 31.205.232.0/21 | 31.205.232.0 | 31.205.232.1 | 31.205.239.254 | 31.205.239.255 | 2,046 |
| 15 | 31.205.240.0/21 | 31.205.240.0 | 31.205.240.1 | 31.205.247.254 | 31.205.247.255 | 2,046 |
| 16 | 31.205.248.0/21 | 31.205.248.0 | 31.205.248.1 | 31.205.255.254 | 31.205.255.255 | 2,046 |