Hexadecimal Number System

Calculate numbers between decimal and hexadecimal systems.

Hexadecimal and IPv6 Addresses

• To understand IPv6 addresses, you must be able to convert hexadecimal to decimal and vice versa.
• Hexadecimal is a base sixteen numbering system, using the digits 0 through 9 and letters A to F.
• It is easier to express a value as a single hexadecimal digit than as four binary bit.
• Hexadecimal is used to represent IPv6 addresses and MAC addresses.

• IPv6 addresses are 128 bits in length. Every 4 bits is represented by a single hexadecimal digit. That makes the IPv6 address a total of 32 hexadecimal values.
• The figure shows the preferred method of writing out an IPv6 address, with each X representing four hexadecimal values.
• Each four hexadecimal character group is referred to as a hextet.

Decimal to Hexadecimal Conversions

• Follow the steps listed to convert decimal numbers to hexadecimal values:
  • Convert the decimal number to 8-bit binary strings.
  • Divide the binary strings in groups of four starting from the rightmost position.
  • Convert each four binary numbers into their equivalent hexadecimal digit.
•   For example, 168 converted into hex using the three-step process.
  • 168 in binary is 10101000.
  • 10101000 in two groups of four binary digits is 1010 and 1000.
  • 1010 is hex A and 1000 is hex 8, so 168 is A8 in hexadecimal.

Hexadecimal to Decimal Conversions

• Follow the steps listed to convert hexadecimal numbers to decimal values:
• • Convert the hexadecimal number to 4-bit binary strings.
  • Create 8-bit binary grouping starting from the rightmost position.
  • Convert each 8-bit binary grouping into their equivalent decimal digit.
•   For example, D2 converted into decimal using the three-step process:
• • D2 in 4-bit binary strings is 1110 and 0010.
  • 1110 and 0010 is 11100010 in an 8-bit grouping.
  • 11100010 in binary is equivalent to 210 in decimal, so D2 is 210 is decimal

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