Home 0P3N Blog The Essential Subnetting Cheat Sheet
Ready to Start Your Career?
Create Free Account
By: SniperCS2
October 28, 2015

The Essential Subnetting Cheat Sheet

By: SniperCS2
October 28, 2015
By: SniperCS2
October 28, 2015
While studying for CCNA many years ago, I created this document to assist me with subnetting.  Hope you find this information helpful. 

Address Space - 32 bit IPV4

 

11111111

11111111

11111111

11111111

 

 

 

Address Grid

   

 

 

Step 1 – Draw Grid

 

Step 2 – Count on fingers by 2 from 2 (2,4,8,16,32,64,128,256)

 

Step3 – 2n-2

 

Step4 – “Can I draw the line here?”

 

Step5 – Magic number sequence (bit * wire number)

 

 

 

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

 

You might also like...

My Journey: CCNA or SECURITY+ 
Request Demo

Build your Cybersecurity or IT Career

Accelerate in your role, earn new certifications, and develop cutting-edge skills using the fastest growing catalog in the industry