3 Network

• Network Interface Card (NIC)


  Allows data transmit between computer and network + device connect to network

  
  

  Allows connected devices to be uniquely identified using MAC addresses
• NIC function

  1. Converting computer's data to format used by the network

  2. follow network protocol rules

  2. vice versa: Converting network data to computer format
• MAC address


  Unique hardware address assigned to a NIC during manufacture
• MAC address structure

  • 48-bit (6bytes) digits
  • First six hex digits - manufacturer id
  • Second six hex digits - device's serial code
• MAC addressfunction: identify unique hardware device:static and unique

  1. data packets sent over network has sender + destination's MAC address

  2. Each NIC or connection checks the mac address, if it matches, it accepts.
• IP address


  • Uniquely identifies a device on a network
  • Can be static (manually assigned) or dynamic (assigned by DHCP)
  • Can be public or private
  • Contains network prefix and host number
• IP address types

  • IPv4 - 32-bit, 4 groups of decimal 0-255.
  • 4 0000.
  • IPv6 - 128-bit, 8 groups of hexadecimal 0-FFFF
  • 8 FFFF:
• IPv4

  • Widely used
  • Address space of 4.3 billion
  • Memory allocated using DHCP or manually
• IPv6

  • Developed to address limitations of IPv4
  • Address space of 340 undecillion
  • Assigned using stateless autoconfiguration
• Router


  • Networking device that directs data packets between networks to correct destination
  • Assigns IP addresses to devices
  • Connects local network/devices to the internet
• Router process

  1. Reads packet header and sends to destination IP address

  2. Uses routing tables to determine appropriate path

  3. Sends packet along the least congested (fastest) path
• Mac address other function

  2. Security:

  identifies unauthorised hardware devices making a connection to a network

  3. Network switch

  1. switch has ports that stores addresses of network devices

  2. switch examines destination addresses

  connects the sender and receiver