Binary and Hexadecimal

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• to interpret a network address, must understand base numbering systems
• decimal numbering is called base 10
  • means that each digit can have one of 10 values (0-9)
• binary is base 2 (0-1)
  • each place position is the next power of 2
  • 11111111 = 255
  • 8 binary digits to represent a decimal value up to 255
  • 8-bit value is called a byte or octet
• IPv4 addresses are expressed as decimal octets (e.g. 201.0.113.1)
• hexadecimal notation is a way of referring to long sequences of bytes
  • used in hardware MAC addresses
  • is base 16
  • represented by 0-9 and A, B, C, D, E, F
  • each byte/octet is expressed by two hex digits (e.g. 255 = FF)
    • sometimes written as 0xFF for clarity