CEH

36 Chapter 2 ■ System Fundamentals

tablE 2.1 Hex, binary, and decimal

Hex Binary Decimal

0 0000 0

1 0001 1

2 0010 2

3 0 011 3

4 0100 4

5 0101 5

6 0110 6

7 0111 7

8 1000 8

9 1001 9

A 1010 10

B 1011 11

C 110 0 12

D 1101 13

E 1110 14

F 1111 15

This should be a refresher for you, but for the exam it is important that you have a com-

fortable understanding of the conversion process. To rehash some of the basics, remember

that bits are 1s and 0s, a nibble is 4 bits, and a byte is 2 nibbles. Your knowledge and

ability to apply this across the conversion process will prove important for questions that

expect you to identify network items and traffic based on hexadecimal values.

TCP flags and their binary or hex values play an integral part in identifying

the type and effectively creating custom scans. You’ll see this in action in

Chapter 5, “Scanning Networks.”