The Essential Subnetting Cheat Sheet

2⁸-2=254

2⁷-2=126

2⁶-2=62

2⁵-2=30

2⁴-2=14

2³-2=6

2²-2=4

2¹-2=0

128

64

32

16

8

4

2

1

1 = 128/25

0

0

0

0

0

0

0

1

1=192/26

0

0

0

0

0

0

1

1

1=224/27

0

0

0

0

0

1

1

1

1=240/28

0

0

0

0

1

1

1

1

1=248/29

0

0

0

1

1

1

1

1

1=252/30

0

0

1

1

1

1

1

1

1=254/32

0

1

1

1

1

1

1

1

1=255

N

128

64

32

16

8

4

2

1

1xN

1 – 128

1 – 64

1 – 32

1 – 16

1 – 8

1 – 4

1 – 2

1 – 1

2xN

2 – 256

2 – 128

2 – 64

2 – 32

2 – 16

2 – 8

2 – 4

2 – 2

3xN

3 – 192

3 – 96

3 – 48

3 – 24

3 – 12

3 – 6

3 – 3

4xN

4 – 256

4 – 128

4 – 64

4 – 32

4 – 16

4 – 8

4 – 4

5xN

5 – 160

5 – 80

5 – 40

5 – 20

5 – 10

5 – 5

6xN

6 – 192

6 – 96

6 – 48

6 – 24

6 – 12

6 – 6

7xN

7 – 224

7 – 112

7 – 56

7 – 28

7 – 14

7 – 7

8 – 256

Up to 16

Up to 32

Up to 64

Up to 128

Up to 256?

Class

IP Range

Subnet

Private Address Range

Class A

1 – 126

255.0.0.0

10.0.0.0 – 10.255.255.255.255

Class B

128 – 191

255.255.0.0

172.16.0.0 – 172.31.255.255

Class C

192 – 223

255.255.255.0

192.168.0.0 – 192.168.255.255

Class D

224 – 239

Multicast

Class E

240 – 255

Experimental

OSI Model

TCP/IP Model

TCP/IP Protocols

Application

Application

HTTP, SMTP, POP3

Presentation

Session

Transport

Transport (TCP/UDP

TCP, UDP

Network

Internet (IP)

IP

Data – Link

Network Access Layer (Ethernet/FDDI)

Ethernet, Frame-Relay, PPP

Physical