Ccna routing and Switching Complete Study Guide

Binary to Decimal and Hexadecimal Conversion

Before we get into working with the TCP/IP protocol and IP addressing, which we’ll do 

in Chapter 3, “Introduction to TCP/IP,” it’s really important for you to truly grasp the 

differences between binary, decimal, and hexadecimal numbers and how to convert one 

format into the other.

We’ll start with binary numbering, which is really pretty simple. The digits used are 

limited to either a 1 or a 0, and each digit is called a bit, which is short for binary digit. 

Typically, you group either 4 or 8 bits together, with these being referred to as a nibble and 

a byte, respectively.

The interesting thing about binary numbering is how the value is represented in a deci-

mal format—the typical decimal format being the base-10 number scheme that we’ve all 

used since kindergarten. The binary numbers are placed in a value spot, starting at the 

right and moving left, with each spot having double the value of the previous spot.

Table 2.1 shows the decimal values of each bit location in a nibble and a byte. 

Remember, a nibble is 4 bits and a byte is 8 bits.

Ta b l E   2 .1     Binary values