3.4 Network hardware

• What does a computer need to access a network? And what does it contain?

  a network interface card (NIC)

  - contains the MAC address. ( generated at manufacturing stage )

  - wireless NIC can be used (plug into USB or be part of internal integrated circuit)
• What is meant by MAC address?

  A unique address that is given to the device by the manufacturer.
• What does MAC stand for?

  Media Access Control
• MAC address structure?

  (48 bits in groups of 6 hex digits)

  NN - NN - NN - DD - DD - DD

  Manufacturer. device serial no.

  code
• What re the diff kind of MAC and why?

  - UAA : universally administered : set at manufacturing stage

  - LAA : locally administered : altered UAA by user

  - can be reset by user if all devices on network need a certain MAC format.
• What is the purpose of a MAC address?

  To uniquely identify a computer on a network
• What is meant by IP address?

  a unique identifying number assigned to every device when it connects to the internet.

  - via a Dynamic Host Configuration protocol : DHCP is unique to that network
• What are the two versions of IP addresses

  IPv4 (32 bit address)( format A.B.C.D )( A,B,C,D take values 1-255)

  IPv6 (128-bit address)( format 8 groups of 4 hex digits ) ( removes risk of IP collisions + allows > efficient packet switching + has built-in authentication checks)
• What does IP address stand for?

  Internet Protocol Address
• What is the purpose of an IP address?


  It is used to uniquely identify the source and destination of data packets on a network.
• Static and Dynamic IP addresses compared :

  
  

  Static

  STATIC

  - permanently assigned

  - don't change so each device is fully traceable

  - allow for faster upload and download speeds

  - device must be constantly running so info is always available --> more expensive to maintain
• Static and Dynamic IP addresses compared :

  
  

  dynamic

  DYNAMIC

  - changes every time a device connects to network

  - > privacy since it changes each time user logs on

  - can be issue when using e.g voice over internet protocol VoIP since this type of addressing is unreliable cause it can disconnect and change IP address --> causes VoIP connection to fail.
• MAC address and IP address differences :

  
  

  MAC (7)

  MAC

  1) identifies physical address of a device on the network

  2) unique for device on network

  3) assigned by manufacturer of device and is part of NIC

  4) can be universal or local

  5) uses 48 bits

  6) can be UAA or LAA

  7) when packet of dat sent + received, MAC is used to identify sender's + recipient's devices
• MAC address and IP address differences :

  
  

  IP (7)

  1) identifies the global addresses on the internet

  2) may not be unique

  3) dynamic IP address assigned by ISP using DHCP each time device connects to internet

  4) dynamic IP address change every time a device connects to internet; static IP addresses don't change

  5) uses either 32 bits(IPv4) or 128 bits (IPv6)

  6) can be static or dynamic

  7) used in routing operations as it specifically identifies where the device is connected to the internet.
• What do routers do?

  - enable data packets to be routed between different networks

  e.g LAN (local area network) or WAN ( wide area network)
• How do Routers work?

  1) take data transmitted in one format ( protocol ) from network 'A'

  2) then convert data to another format ( protocol ) that network 'B' understands
• Why do routers inspect data packets sent to it from another device or network?

  - every device on same network has same part of IP address, so router can send data packets to an appropriate switch

  - switch then directs data packets to the correct device on the network
• Sample Q : Explain the different function of a MAC address and an IP address of a device connected to the internet. Also include any similarities in the 2 types of addressing.


  - MAC address identifies the physical address of a device on internet, whereas IP address identifies the device's global address on the internet

  
  

  - MAC addresses are unique for each device, however IP addresses are not necessarily unique since all devices on a network share the same part of an IP address

  
  

  - MAC addresses can be set by manufacturer but can also be changed by user. IP can also be dynamic or static ( usually assigned by DHCP server)

  
  

  - MAC used to identify a data packet's sender and recipient; IP used in routing operations as they specifically indentify where teh device is connected to the internet.
• 3 descriptions of network terms are given below. Name network term being described :

  
  

  a ) Hardware component (on circuit board) that allows a device to connect to network.

  B) unique identifier that acts as a network address for a device; takes form NN-NN-NN-DD-DD-DD

  C) Server automatically provides and assigns an IP address to a device when it first connects to the internet.

  a) a NIC

  b) MAC address

  c) Dynamic Host Configuration Protocol server ( DHCP ) server
• 2 descriptions of network terms are given below. Name network term being described :

  
  

  a) Device that allows data packets to be moved between different networks

  
  

  B) address given to a device so that its global position on a network is known

  a) router

  b) IP address