Networking Week 8

A link where data can flow successfully in both directions at the same time is
operating in:

• Half duplex mode

• Full duplex mode

• 
  Simplex mode

• Multiplex mode

A message is to be sent from a host on an Ethernet network to a host on a remote
network. What MAC address does the host use as the destination address in the frame
header?

• 
  The MAC address of the host on the remote network.

• 
  Its own MAC address.

• 
  The MAC address of the local switch.

• The MAC address of the default gateway

A network with a point to point topology: (choose 2)

• 
  Has only 2 nodes

  
  

• Must be run in half duplex mode

• Can have a simpler form of media access control than a multi-access network

• 
  Is subject to collisions because it has a less sophisticated form of Layer 2
  protocol

A physical network topology shows:

• How devices are linked by cables or wireless connections

• How the network is split into subnets

• How access to the medium is controlled

• 
  How the layer 2 and layer 3 addresses are matched

Encapsulation at the data link layer involves

• Adding a header

• 
  Adding a trailer

• Adding a header and a trailer

• Changing the IP address to a MAC address

How are data link layer Ethernet addresses normally written down?

• In dotted decimal form

• 
  As groups of 2 or 4 hexadecimal digits

• 
  In binary as octets

• 
  In octal

How many bits are there in a data link layer Ethernet address?

• 16

• 32

• 48

• 64

• 128

How would a host on an Ethernet network detect that there is an incoming frame
starting to arrive?

• 
  Each frame starts with a preamble, originally used for synchronisation, and the
  preamble ends with a frame start delimiter.

• Frames arrive at fixed intervals so it can predict when the next frame will
  arrive.

• 
  The destination address is the first field in the frame, so the host detects a
  frame when it recognises its own address.

• 
  When there is no incoming frame the medium is completely clear, so the host
  just checks for any activity.

The logical topology determines

• The arrangement of PCs within a building

• 
  The method of media access control

• 
  The type of gateway router required

• The layer 3 protocol to be used

What are the two sublayers of the data link layer?

• Physical access and network access sublayers

• Logical link control and network access sublayers

• Logical link control and media access control sublayers

• CSMA/CD sublayer and media access control sublayer