IP
Addressing Guide
Class
A first octet range 1 – 127* (Network 127 is reserved for loopback
and internal testing) Leading bit pattern 0
Class
B first octet range 128 – 191 Leading bit pattern 10
Class
C first octet range 192 – 223 Leading bit pattern 110
Class
D first octet range 224 – 239 (Reserved for multicast) Leading bit pattern 1110
Class
E first octet range 240 –
255 (Reserved for experimental, used for
research) Leading bit pattern 11110
Class A 27 – 2 = 126 Class B 214 – 2 = 16,382 Class
C
221 – 2 = 2,097,150
M = the number
of bits borrowed (Masked)
U = the number of bits remaining or not borrowed (Unmasked)
2M = Total # of subnets created 2U
= Total # of host on each subnets
2M – 2 = Useable # of subnet created 2U – 2 =
Useable # of host on each subnet
Class A License
|
N.H.H.H |
|
|
|
|
Class B License |
N.N.H.H |
|
|
|
||
# of Bits Borrowed |
Subnet Mask |
Total # Subnets |
Useable # Subnets |
Total # Hosts |
Useable
# Hosts |
# of Bits Borrowed |
Subnet Mask |
Total # Subnets |
Useable # Subnets |
Total # Hosts |
Useable # Hosts |
|
2 |
255.192.0.0 |
4 |
2 |
4,194,304 |
4,194,302 |
|
2 |
255.255.192.0 |
4 |
2 |
16,384 |
16,382 |
3 |
255.224.0.0 |
8 |
6 |
2,097,152 |
2,097,150 |
|
3 |
255.255.224.0 |
8 |
6 |
8,192 |
8,190 |
4 |
255.240.0.0 |
16 |
14 |
1,048,576 |
1,048,574 |
|
4 |
255.255.240.0 |
16 |
14 |
4,096 |
4,094 |
5 |
255.248.0.0 |
32 |
30 |
524,288 |
524,286 |
|
5 |
255.255.248.0 |
32 |
30 |
2,048 |
2,046 |
6 |
255.252.0.0 |
64 |
62 |
262,144 |
262,142 |
|
6 |
255.255.252.0 |
64 |
62 |
1,024 |
1,022 |
7 |
255.254.0.0 |
128 |
126 |
131,072 |
131,070 |
|
7 |
255.255.254.0 |
128 |
126 |
512 |
510 |
8 |
255.255.0.0 |
256 |
254 |
65,536 |
65,534 |
|
8 |
255.255.255.0 |
256 |
254 |
256 |
254 |
9 |
255.255.128.0 |
512 |
510 |
32,768 |
32,766 |
|
9 |
255.255.255.128 |
512 |
510 |
128 |
126 |
10 |
255.255.192.0 |
1,024 |
1,022 |
16,384 |
16,382 |
|
10 |
255.255.255.192 |
1,024 |
1,022 |
64 |
62 |
11 |
255.255.224.0 |
2,048 |
2,046 |
8,192 |
8,190 |
|
11 |
255.255.255.224 |
2,048 |
2,046 |
32 |
30 |
12 |
255.255.240.0 |
4,096 |
4,094 |
4,096 |
4,094 |
|
12 |
255.255.255.240 |
4,096 |
4,094 |
16 |
14 |
13 |
255.255.248.0 |
8,192 |
8,190 |
2,048 |
2,046 |
|
13 |
255.255.255.248 |
8,192 |
8,190 |
8 |
6 |
14 |
255.255.252.0 |
16,384 |
16,382 |
1,024 |
1,022 |
|
14 |
255.255.255.252 |
16,384 |
16,382 |
4 |
2 |
15 |
255.255.254.0 |
32,768 |
32,766 |
512 |
510 |
|
|
|
|
|
|
|
16 |
255.255.255.0 |
65,536 |
65,534 |
256 |
254 |
|
Class C License |
N.N.N.H |
|
|
|
|
17 |
255.255.255.128 |
131,072 |
131,070 |
128 |
126 |
|
# of Bits |
|
Total # |
Useable # |
Total # |
Useable |
18 |
255.255.255.192 |
262,144 |
262,142 |
64 |
62 |
|
Borrowed |
Subnet Mask |
Subnets |
Subnets |
Hosts |
# Hosts |
19 |
255.255.255.224 |
524,288 |
524,286 |
32 |
30 |
|
2 |
255.255.255.192 |
4 |
2 |
64 |
62 |
20 |
255.255.255.240 |
1,048,576 |
1,048,574 |
16 |
14 |
|
3 |
255.255.255.224 |
8 |
6 |
32 |
30 |
21 |
255.255.255.248 |
2,097,152 |
2,097,150 |
8 |
6 |
|
4 |
255.255.255.240 |
16 |
14 |
16 |
14 |
22 |
255.255.255.252 |
4,194,304 |
4,194,302 |
4 |
2 |
|
5 |
255.255.255.248 |
32 |
30 |
8 |
6 |
|
|
|
|
|
|
|
6 |
255.255.255.252 |
64 |
62 |
4 |
2 |
NOTE: You must borrow at least 2
bits and you must leave at least 2 bits.
G. Wright