/2 Subnet
1,073,741,824 total IPs — 1,073,741,822 usable hosts.
Example /2 Networks
| CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|
| 0.0.0.0/2 | 0.0.0.0 | 0.0.0.1 | 63.255.255.254 | 63.255.255.255 | 1,073,741,822 |
| 128.0.0.0/2 | 128.0.0.0 | 128.0.0.1 | 191.255.255.254 | 191.255.255.255 | 1,073,741,822 |
| 128.0.0.0/2 | 128.0.0.0 | 128.0.0.1 | 191.255.255.254 | 191.255.255.255 | 1,073,741,822 |
| 192.0.0.0/2 | 192.0.0.0 | 192.0.0.1 | 255.255.255.254 | 255.255.255.255 | 1,073,741,822 |
| 192.0.0.0/2 | 192.0.0.0 | 192.0.0.1 | 255.255.255.254 | 255.255.255.255 | 1,073,741,822 |
| 0.0.0.0/2 | 0.0.0.0 | 0.0.0.1 | 63.255.255.254 | 63.255.255.255 | 1,073,741,822 |
How /2 Compares
| Prefix | Total IPs | Usable Hosts | Subnet Mask | Typical Use |
|---|---|---|---|---|
| /0 | 4,294,967,296 | 4,294,967,294 | 0.0.0.0 | Routing & firewalls only |
| /1 | 2,147,483,648 | 2,147,483,646 | 128.0.0.0 | — |
| /2 ◀ | 1,073,741,824 | 1,073,741,822 | 192.0.0.0 | — |
| /3 | 536,870,912 | 536,870,910 | 224.0.0.0 | — |
| /4 | 268,435,456 | 268,435,454 | 240.0.0.0 | — |
| /5 | 134,217,728 | 134,217,726 | 248.0.0.0 | — |
Frequently Asked Questions
How many IPs are in a /2?
A /2 subnet contains 1,073,741,824 total IP addresses and 1,073,741,822 usable host addresses. The network address (first IP) and broadcast address (last IP) are reserved and cannot be assigned to hosts.
What is the subnet mask for /2?
The subnet mask for a /2 is 192.0.0.0.
In CIDR notation, the prefix length /2 means
the first 2 bits of the address are the network portion.
The wildcard (inverse) mask is 63.255.255.255.
How many /2 subnets fit in a /1?
Exactly 2 — a /1 can be split into two /2 subnets of equal size.