231.19.128.0/20
Multicast RFC 5771Class D (Multicast) — /20 prefix — 4,094 usable hosts
Network address — the base address of the block (231.19.128.0). All devices in this subnet share this prefix. Cannot be assigned to a host.
Broadcast address — packets sent to 231.19.143.255 are delivered to every device in the subnet. Also reserved — not assignable.
Usable hosts — the 4,094 addresses between those two that you can assign to servers, VMs, or interfaces.
Subnet mask — 255.255.240.0 is the dotted-decimal equivalent of /20. Older tools and Cisco configs use this format instead of CIDR slash notation.
Full Details
| CIDR Notation | 231.19.128.0/20 |
| Network Address | 231.19.128.0 |
| Broadcast Address | 231.19.143.255 |
| Subnet Mask | 255.255.240.0 |
| Wildcard Mask | 0.0.15.255 |
| Prefix Length | /20 |
| IP Address Class | Class D (Multicast) |
| Total IP Addresses | 4,096 |
| Usable Host Addresses | 4,094 |
| First Usable IP | 231.19.128.1 |
| Last Usable IP | 231.19.143.254 |
| Network (Hex) | 0xE7138000 |
| Broadcast (Hex) | 0xE7138FFF |
| Governing RFC | RFC 5771 |
| Address Type | Multicast |
Binary Representation
The first 20 bits (1s in the mask) identify the network. The remaining 12 bits identify hosts within the network.
Split into Equal Subnets
Split 231.19.128.0/20 into 2 equal /21 subnets (2,046 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 231.19.128.0/21 | 231.19.128.0 | 231.19.128.1 | 231.19.135.254 | 231.19.135.255 | 2,046 |
| 2 | 231.19.136.0/21 | 231.19.136.0 | 231.19.136.1 | 231.19.143.254 | 231.19.143.255 | 2,046 |
Split 231.19.128.0/20 into 4 equal /22 subnets (1,022 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 231.19.128.0/22 | 231.19.128.0 | 231.19.128.1 | 231.19.131.254 | 231.19.131.255 | 1,022 |
| 2 | 231.19.132.0/22 | 231.19.132.0 | 231.19.132.1 | 231.19.135.254 | 231.19.135.255 | 1,022 |
| 3 | 231.19.136.0/22 | 231.19.136.0 | 231.19.136.1 | 231.19.139.254 | 231.19.139.255 | 1,022 |
| 4 | 231.19.140.0/22 | 231.19.140.0 | 231.19.140.1 | 231.19.143.254 | 231.19.143.255 | 1,022 |
Split 231.19.128.0/20 into 8 equal /23 subnets (510 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 231.19.128.0/23 | 231.19.128.0 | 231.19.128.1 | 231.19.129.254 | 231.19.129.255 | 510 |
| 2 | 231.19.130.0/23 | 231.19.130.0 | 231.19.130.1 | 231.19.131.254 | 231.19.131.255 | 510 |
| 3 | 231.19.132.0/23 | 231.19.132.0 | 231.19.132.1 | 231.19.133.254 | 231.19.133.255 | 510 |
| 4 | 231.19.134.0/23 | 231.19.134.0 | 231.19.134.1 | 231.19.135.254 | 231.19.135.255 | 510 |
| 5 | 231.19.136.0/23 | 231.19.136.0 | 231.19.136.1 | 231.19.137.254 | 231.19.137.255 | 510 |
| 6 | 231.19.138.0/23 | 231.19.138.0 | 231.19.138.1 | 231.19.139.254 | 231.19.139.255 | 510 |
| 7 | 231.19.140.0/23 | 231.19.140.0 | 231.19.140.1 | 231.19.141.254 | 231.19.141.255 | 510 |
| 8 | 231.19.142.0/23 | 231.19.142.0 | 231.19.142.1 | 231.19.143.254 | 231.19.143.255 | 510 |
Split 231.19.128.0/20 into 16 equal /24 subnets (254 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 231.19.128.0/24 | 231.19.128.0 | 231.19.128.1 | 231.19.128.254 | 231.19.128.255 | 254 |
| 2 | 231.19.129.0/24 | 231.19.129.0 | 231.19.129.1 | 231.19.129.254 | 231.19.129.255 | 254 |
| 3 | 231.19.130.0/24 | 231.19.130.0 | 231.19.130.1 | 231.19.130.254 | 231.19.130.255 | 254 |
| 4 | 231.19.131.0/24 | 231.19.131.0 | 231.19.131.1 | 231.19.131.254 | 231.19.131.255 | 254 |
| 5 | 231.19.132.0/24 | 231.19.132.0 | 231.19.132.1 | 231.19.132.254 | 231.19.132.255 | 254 |
| 6 | 231.19.133.0/24 | 231.19.133.0 | 231.19.133.1 | 231.19.133.254 | 231.19.133.255 | 254 |
| 7 | 231.19.134.0/24 | 231.19.134.0 | 231.19.134.1 | 231.19.134.254 | 231.19.134.255 | 254 |
| 8 | 231.19.135.0/24 | 231.19.135.0 | 231.19.135.1 | 231.19.135.254 | 231.19.135.255 | 254 |
| 9 | 231.19.136.0/24 | 231.19.136.0 | 231.19.136.1 | 231.19.136.254 | 231.19.136.255 | 254 |
| 10 | 231.19.137.0/24 | 231.19.137.0 | 231.19.137.1 | 231.19.137.254 | 231.19.137.255 | 254 |
| 11 | 231.19.138.0/24 | 231.19.138.0 | 231.19.138.1 | 231.19.138.254 | 231.19.138.255 | 254 |
| 12 | 231.19.139.0/24 | 231.19.139.0 | 231.19.139.1 | 231.19.139.254 | 231.19.139.255 | 254 |
| 13 | 231.19.140.0/24 | 231.19.140.0 | 231.19.140.1 | 231.19.140.254 | 231.19.140.255 | 254 |
| 14 | 231.19.141.0/24 | 231.19.141.0 | 231.19.141.1 | 231.19.141.254 | 231.19.141.255 | 254 |
| 15 | 231.19.142.0/24 | 231.19.142.0 | 231.19.142.1 | 231.19.142.254 | 231.19.142.255 | 254 |
| 16 | 231.19.143.0/24 | 231.19.143.0 | 231.19.143.1 | 231.19.143.254 | 231.19.143.255 | 254 |