CCNA Exploration Chapter 7 data link layer. Study questions.

7.1

What are the two basic services at the data link layer?

 it on the media.

What is the name of the Data Link layer PDU?

 

What are media (in the context of OSI layers 1 and 2)?

 

What are Nodes ?

 

What is a physical network?

 

The sending host encapsulates the packet into a frame before putting it on the transmission medium. Does the frame stay the same until it reaches its final destination?

 

Why does IP not have to change every time there are developments in transmission media (e.g. introduction of Ethernet speeds greater than 1Gbps)?

 

Which part of a PC is responsible for carrying out data link functions and placing messages on the medium?

 

Why do routers often have more than one type of physical interface (port)?

 

There is only one network layer protocol (IP) generally used on the Internet for addressing and encapsulating packets. Why are there several different data link layer protocols in common use on the Internet?

 

The transport layer and the network layer add addressing and control information to the data in the form of a header. How is the data link layer different?

 

What is the purpose of the first field in a frame header?

 

What other fields are typically found in a frame header?

 

What fields are typically found in a frame trailer?

 

What are the two data link sublayers, and what is their function?

 

Why can it be useful to divide the data link layer into sublayers?

 

What is defined by IEEE 802.11

 

What is defined by !EEE 802.3

7.2

What are shared media, and why do they need media access control?

 

What are the characteristics of controlled access or deterministic media access control?

 

What are the advantages and disadvantages of controlled access?

 

Which LAN technologies use controlled access?

 

What are the characteristics of contention based media access control?

 

What are the advantages and disadvantages of contention based media access control?

 

Which LAN technologies use contention based media access control?

 

What is the advantage of using full duplex communication on a point-to-point link?

 

What is the physical topology of a network?

 

What is the logical topology of a network?

 

A network has a logical ring topology. Does it necessarily have a physical ring topology?

 

Which logical topology typically uses CSMA/CD or CSMA/CA as a media access control method?

 

7.3

What is the name given to addresses added at the data link layer?

 

If a data link layer address is used only for delivery on the local network, how can a message be sent to a remote network?

 

What is the purpose of the FCS field in the frame trailer?

 

If an error is found in a frame, can it be corrected?

 

Why do LANs and WANs use different data link layer protocols?

 

What remains the same for all versions of Ethernet, operating at defferent speeds?

 

What is a MAC address?

 

How many bits are in a MAC address and how is it written?

 

A host on an Ethernet network is sending a message to a destination host on a remote network. It puts the IP address of the destination host in the packet header. What destination address will it put in the frame header?

 

Why does a PPP frame not contain full layer 2 addresses?

 

What physical media does PPP use?

 

PPP sets up sessions. What options can the two nodes negotiate within a session?

 

Which standard is commonly called WiFi?

 

What does WiFi have in common with Ethernet?

 

It uses the same logical link control layer protocols and the same addressing scheme. It is also susceptible to collisions (but deals with them differently).