Hexadecimal
The CCNA exam(s) will ask you a few questions on the conversion of binary to hexadecimal and back, so you need to understand how it works. An understanding of hex is also a useful skill for other areas of networking and computer science.
Binary is Base2; Decimal is Base10; Hexadecimal is Base16. Each column in hex can represent 16 possible values, from 0 through 15. In order to represent a value of 10 through 15 with a single character, hex uses the letters A through F. It is important to understand that the values of 0 through 15 are the possible values of a 4-bit binary number, as shown in Table 3.6.
Table 3.6. Decimal, Binary, and Hex Values Compared
Decimal |
Binary |
Hex |
0 |
0000 |
0 |
1 |
0001 |
1 |
2 |
0010 |
2 |
3 |
0011 |
3 |
4 |
0100 |
4 |
5 |
0101 |
5 |
6 |
0110 |
6 |
7 |
0111 |
7 |
8 |
1000 |
8 |
9 |
1001 |
9 |
10 |
1010 |
A |
11 |
1011 |
B |
12 |
1100 |
C |
13 |
1101 |
D |
14 |
1110 |
E |
15 |
1111 |
F |