121.90.192.0/19
PublicClass A — /19 prefix — 8,190 usable hosts
Network address — the base address of the block (121.90.192.0). All devices in this subnet share this prefix. Cannot be assigned to a host.
Broadcast address — packets sent to 121.90.223.255 are delivered to every device in the subnet. Also reserved — not assignable.
Usable hosts — the 8,190 addresses between those two that you can assign to servers, VMs, or interfaces.
Subnet mask — 255.255.224.0 is the dotted-decimal equivalent of /19. Older tools and Cisco configs use this format instead of CIDR slash notation.
Full Details
| CIDR Notation | 121.90.192.0/19 |
| Network Address | 121.90.192.0 |
| Broadcast Address | 121.90.223.255 |
| Subnet Mask | 255.255.224.0 |
| Wildcard Mask | 0.0.31.255 |
| Prefix Length | /19 |
| IP Address Class | Class A |
| Total IP Addresses | 8,192 |
| Usable Host Addresses | 8,190 |
| First Usable IP | 121.90.192.1 |
| Last Usable IP | 121.90.223.254 |
| Network (Hex) | 0x795AC000 |
| Broadcast (Hex) | 0x795ADFFF |
| Address Type | Public / Globally Routable |
Binary Representation
The first 19 bits (1s in the mask) identify the network. The remaining 13 bits identify hosts within the network.
Split into Equal Subnets
Split 121.90.192.0/19 into 2 equal /20 subnets (4,094 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 121.90.192.0/20 | 121.90.192.0 | 121.90.192.1 | 121.90.207.254 | 121.90.207.255 | 4,094 |
| 2 | 121.90.208.0/20 | 121.90.208.0 | 121.90.208.1 | 121.90.223.254 | 121.90.223.255 | 4,094 |
Split 121.90.192.0/19 into 4 equal /21 subnets (2,046 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 121.90.192.0/21 | 121.90.192.0 | 121.90.192.1 | 121.90.199.254 | 121.90.199.255 | 2,046 |
| 2 | 121.90.200.0/21 | 121.90.200.0 | 121.90.200.1 | 121.90.207.254 | 121.90.207.255 | 2,046 |
| 3 | 121.90.208.0/21 | 121.90.208.0 | 121.90.208.1 | 121.90.215.254 | 121.90.215.255 | 2,046 |
| 4 | 121.90.216.0/21 | 121.90.216.0 | 121.90.216.1 | 121.90.223.254 | 121.90.223.255 | 2,046 |
Split 121.90.192.0/19 into 8 equal /22 subnets (1,022 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 121.90.192.0/22 | 121.90.192.0 | 121.90.192.1 | 121.90.195.254 | 121.90.195.255 | 1,022 |
| 2 | 121.90.196.0/22 | 121.90.196.0 | 121.90.196.1 | 121.90.199.254 | 121.90.199.255 | 1,022 |
| 3 | 121.90.200.0/22 | 121.90.200.0 | 121.90.200.1 | 121.90.203.254 | 121.90.203.255 | 1,022 |
| 4 | 121.90.204.0/22 | 121.90.204.0 | 121.90.204.1 | 121.90.207.254 | 121.90.207.255 | 1,022 |
| 5 | 121.90.208.0/22 | 121.90.208.0 | 121.90.208.1 | 121.90.211.254 | 121.90.211.255 | 1,022 |
| 6 | 121.90.212.0/22 | 121.90.212.0 | 121.90.212.1 | 121.90.215.254 | 121.90.215.255 | 1,022 |
| 7 | 121.90.216.0/22 | 121.90.216.0 | 121.90.216.1 | 121.90.219.254 | 121.90.219.255 | 1,022 |
| 8 | 121.90.220.0/22 | 121.90.220.0 | 121.90.220.1 | 121.90.223.254 | 121.90.223.255 | 1,022 |
Split 121.90.192.0/19 into 16 equal /23 subnets (510 usable hosts each).
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 121.90.192.0/23 | 121.90.192.0 | 121.90.192.1 | 121.90.193.254 | 121.90.193.255 | 510 |
| 2 | 121.90.194.0/23 | 121.90.194.0 | 121.90.194.1 | 121.90.195.254 | 121.90.195.255 | 510 |
| 3 | 121.90.196.0/23 | 121.90.196.0 | 121.90.196.1 | 121.90.197.254 | 121.90.197.255 | 510 |
| 4 | 121.90.198.0/23 | 121.90.198.0 | 121.90.198.1 | 121.90.199.254 | 121.90.199.255 | 510 |
| 5 | 121.90.200.0/23 | 121.90.200.0 | 121.90.200.1 | 121.90.201.254 | 121.90.201.255 | 510 |
| 6 | 121.90.202.0/23 | 121.90.202.0 | 121.90.202.1 | 121.90.203.254 | 121.90.203.255 | 510 |
| 7 | 121.90.204.0/23 | 121.90.204.0 | 121.90.204.1 | 121.90.205.254 | 121.90.205.255 | 510 |
| 8 | 121.90.206.0/23 | 121.90.206.0 | 121.90.206.1 | 121.90.207.254 | 121.90.207.255 | 510 |
| 9 | 121.90.208.0/23 | 121.90.208.0 | 121.90.208.1 | 121.90.209.254 | 121.90.209.255 | 510 |
| 10 | 121.90.210.0/23 | 121.90.210.0 | 121.90.210.1 | 121.90.211.254 | 121.90.211.255 | 510 |
| 11 | 121.90.212.0/23 | 121.90.212.0 | 121.90.212.1 | 121.90.213.254 | 121.90.213.255 | 510 |
| 12 | 121.90.214.0/23 | 121.90.214.0 | 121.90.214.1 | 121.90.215.254 | 121.90.215.255 | 510 |
| 13 | 121.90.216.0/23 | 121.90.216.0 | 121.90.216.1 | 121.90.217.254 | 121.90.217.255 | 510 |
| 14 | 121.90.218.0/23 | 121.90.218.0 | 121.90.218.1 | 121.90.219.254 | 121.90.219.255 | 510 |
| 15 | 121.90.220.0/23 | 121.90.220.0 | 121.90.220.1 | 121.90.221.254 | 121.90.221.255 | 510 |
| 16 | 121.90.222.0/23 | 121.90.222.0 | 121.90.222.1 | 121.90.223.254 | 121.90.223.255 | 510 |