click the C subnets you want. Or, subnetting to C-size or smaller subnets.
No vertical overlaps (unclick red).
Top row is default C network, i.e. not subnetted.
Number is the value of the fourth octet of the network address
of the subnet.
First column is the mask prefix and the value of the mask's fourth octet.
| /24 .0 | 0 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| /25 .128 | 0 | 128 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| /26 .192 | 0 | 64 | 128 | 192 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| /27 .224 | 0 | 32 | 64 | 96 | 128 | 160 | 192 | 224 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| /28 .240 | 0 | 16 | 32 | 48 | 64 | 80 | 96 | 112 | 128 | 144 | 160 | 176 | 192 | 208 | 224 | 240 | ||||||||||||||||||||||||||||||||||||||||||||||||
| /29 .248 | 0 | 8 | 16 | 24 | 32 | 40 | 48 | 56 | 64 | 72 | 80 | 88 | 96 | 104 | 112 | 120 | 128 | 136 | 144 | 152 | 160 | 168 | 176 | 182 | 192 | 200 | 208 | 216 | 224 | 232 | 240 | 248 | ||||||||||||||||||||||||||||||||
| /30 .252 | 0 | 4 | 8 | 12 | 16 | 20 | 24 | 28 | 32 | 36 | 40 | 44 | 48 | 52 | 56 | 60 | 64 | 68 | 72 | 76 | 80 | 84 | 88 | 92 | 96 | 100 | 104 | 108 | 112 | 116 | 120 | 124 | 128 | 132 | 136 | 140 | 144 | 148 | 152 | 156 | 160 | 164 | 168 | 172 | 176 | 180 | 184 | 188 | 192 | 196 | 200 | 204 | 208 | 212 | 216 | 220 | 224 | 228 | 232 | 236 | 240 | 244 | 248 | 252 |
Classful addressing is officially obsoleted by classless addressing
(CIDR: classless inter-domain routing).
In classless addressing, boundary between network ID part of the IP address
and the host ID part of the IP address can be anywhere using a
variable-length subnet mask (VLSM), which allows networks to have any power of 2 (-2)
hosts i.e. 2, 6, 14, 30, 62, 126, 510, 1022, etc.
A network can be subnetted into smaller networks.
Also, smaller networks can be aggregated into a larger network with supernetting.
Subnetting such that all the subnets are the same size and have the same mask: FLSM
(fixed length subnet mask).
Private addresses. Class A 10.0.0.0 network can be subnetted into 16K C-size subnets. Each class B 172.16-31.0.0 network can be subnetted into 256 C-size subnets, for a total of 4K C-size subnets.