Masked bit | mask value | Number of subnets | Number of hosts/subnets | Approximate number of host/subnets |
/20 | 255.255.240.0 | 5c | 4096 | 4000 |
/21 | 255.255.248.0 | 4c | 2048 | 2000 |
/22 | 255.255.252.0 | 3c | 1024 | 1000 |
/23 | 255.255.254.0 | 2c | 512 | 500 |
/24 | 255.255.255.0 | 1c | 256 | 250 |
/25 | 255..255.255.128 | ½c | 128 | 125 |
/26 | 255.255..255..192 | ¼c | 64 | 60 |
/27 | 255.255.255.224 | 1/8 c | 32 | 30 |
/28 | 255.255.255.240 | 1/16 c | 16 | 15 |
IP Addressing Facts:-
The following table lists the default IP addressing classes and masks:
Class | Address range | Default mast |
A | 1.0.0.0 to 126.255.255.255 | 255.0.0.0 |
B | 128.0.0.0 to 191.255.255.255 | 255.255.0.0 |
C | 192.0.0.0 to 223.255.255.255 | 255.255.255.0 |
D | 224.0.0.0 to 239.255.255.255 | (multicast addresses) |
E | 240.0.0.0 to 255.255.255.255 | (experimental addresses) |
