Site hosted by Angelfire.com: Build your free website today!
Class Subnet Bits Possible Subnets Usuable Subnets Host Bits Possible Hosts Usable Hosts Subnet Bit Map
C 2 4 2 6 64 62 110NNNNN.NNNNNNNN.NNNNNNNN.SSHHHHHH
C 3 8 6 5 32 30 110NNNNN.NNNNNNNN.NNNNNNNN.SSSHHHHH
C 4 16 14 4 16 14 110NNNNN.NNNNNNNN.NNNNNNNN.SSSSHHHH
C 5 32 30 3 8 6 110NNNNN.NNNNNNNN.NNNNNNNN.SSSSSHHH
C 6 64 62 2 4 2 110NNNNN.NNNNNNNN.NNNNNNNN.SSSSSSHH
B 2 4 2 14 16,384 16,382 10NNNNNN.NNNNNNNN.SSHHHHHH.HHHHHHHH
B 3 8 6 13 8,192 8,190 10NNNNNN.NNNNNNNN.SSSHHHHH.HHHHHHHH
B 4 16 14 12 4,096 4,094 10NNNNNN.NNNNNNNN.SSSSHHHH.HHHHHHHH
B 5 32 30 11 2,048 2,046 10NNNNNN.NNNNNNNN.SSSSSHHH.HHHHHHHH
B 6 64 62 10 1,024 1,022 10NNNNNN.NNNNNNNN.SSSSSSHH.HHHHHHHH
B 7 128 126 9 512 510 10NNNNNN.NNNNNNNN.SSSSSSSH.HHHHHHHH
B 8 256 254 8 256 254 10NNNNNN.NNNNNNNN.SSSSSSSS.HHHHHHHH
B 9 512 510 7 128 126 10NNNNNN.NNNNNNNN.SSSSSSSS.SHHHHHHH
B 10 1,024 1,022 6 64 62 10NNNNNN.NNNNNNNN.SSSSSSSS.SSHHHHHH
B 11 2,048 2,046 5 32 30 10NNNNNN.NNNNNNNN.SSSSSSSS.SSSHHHHH
B 12 4,096 4,094 4 16 14 10NNNNNN.NNNNNNNN.SSSSSSSS.SSSSHHHH
B 13 8,192 8,190 3 8 6 10NNNNNN.NNNNNNNN.SSSSSSSS.SSSSSHHH
B 14 16,384 16,382 2 4 2 10NNNNNN.NNNNNNNN.SSSSSSSS.SSSSSSHH
A 2 4 2 22 4,192,304 4,192,302 0NNNNNNN.SSHHHHHH.HHHHHHHH.HHHHHHHH
A 3 8 6 21 2,097,152 2,097,150 0NNNNNNN.SSSHHHHH.HHHHHHHH.HHHHHHHH
A 4 16 14 20 1,048,576 1,048,574 0NNNNNNN.SSSSHHHH.HHHHHHHH.HHHHHHHH
A 5 32 30 19 524,288 524,286 0NNNNNNN.SSSSSHHH.HHHHHHHH.HHHHHHHH
A 6 64 62 18 262,144 262,142 0NNNNNNN.SSSSSSHH.HHHHHHHH.HHHHHHHH
A 7 128 126 17 131,072 131,070 0NNNNNNN.SSSSSSSH.HHHHHHHH.HHHHHHHH
A 8 256 254 16 65,536 65,534 0NNNNNNN.SSSSSSSS.HHHHHHHH.HHHHHHHH
A 9 512 510 15 32,768 32,766 0NNNNNNN.SSSSSSSS.SHHHHHHH.HHHHHHHH
A 10 1,024 1,022 14 16,384 16,382 0NNNNNNN.SSSSSSSS.SSHHHHHH.HHHHHHHH
A 11 2,048 2,046 13 8,192 8,190 0NNNNNNN.SSSSSSSS.SSSHHHHH.HHHHHHHH
A 12 4,096 4,094 12 4,096 4,094 0NNNNNNN.SSSSSSSS.SSSSHHHH.HHHHHHHH
A 13 8,192 8,190 11 2,048 2,046 0NNNNNNN.SSSSSSSS.SSSSSHHH.HHHHHHHH
A 14 16,384 16,382 10 1,024 1,022 0NNNNNNN.SSSSSSSS.SSSSSSHH.HHHHHHHH
A 15 32,768 32,766 9 512 510 0NNNNNNN.SSSSSSSS.SSSSSSSH.HHHHHHHH
A 16 65,536 65,534 8 256 254 0NNNNNNN.SSSSSSSS.SSSSSSSS.HHHHHHHH
A 17 131,072 131,070 7 128 126 0NNNNNNN.SSSSSSSS.SSSSSSSS.SHHHHHHH
A 18 262,144 262,142 6 64 62 0NNNNNNN.SSSSSSSS.SSSSSSSS.SSHHHHHH
A 19 524,288 524,286 5 32 30 0NNNNNNN.SSSSSSSS.SSSSSSSS.SSSHHHHH
A 20 1,048,576 1,048,574 4 16 14 0NNNNNNN.SSSSSSSS.SSSSSSSS.SSSSHHHH
A 21 2,097,152 2,097,150 3 8 6 0NNNNNNN.SSSSSSSS.SSSSSSSS.SSSSSHHH
A 22 4,194,304 4,194,302 2 4 2 0NNNNNNN.SSSSSSSS.SSSSSSSS.SSSSsSHH

20=1 28=256 216=65,536 224=16,777,216
21=2 29=512 217=131,072 225=33,554,432
22=4 210=1,024 218=262,144 226=67,108,864
23=8 211=2,048 219=524,288 227=134,217,728
24=16 212=4,096 220=1,048,576 228=268,435,456
25=32 213=8,192 221=2,097,152 229=536,870,912
26=64 214=16,384 222=4,194,304 230=1,073,741,824
27=128 215=32,768 223=8,388,608 231=2,147,483,648

32 bits = 4 octets of 8 bits each = 11111111.11111111.11111111.11111111

Each bit in each octet can have a binary placement value.

The 8 bits in the first octet:
231 230 229 228 227 226 225 224

The 8 bits in the second octet:
223 222 221 220 219 218 217 216

The 8 bits in the third octet:
215 214 213 212 211 210 29 28

The 8 bits in the fourth octet:
27 26 25 24 23 22 21 20

IP Addresses are 32 bits long.

Some subnet calculations are accomplished using all 32 bits and their corresponding binary positions: 20 - 231.

Some subnet calculations are accomplished using 4 groups of 8, each octet never increasing beyond 27.