Chapter 1 -Internetworking Basics

Question 1

What is a MAC address

Answer 1

Also known as a hardware address, it is burned right into the NIC.

Question 2

Network Segmentation

Answer 2

Breaking up a really big network into a number of smaller ones.
Done by using bridges, switches and routers.

Question 3

What are some common causes of LAN traffic congestion?

Answer 3

1. Too many hosts in a broadcast or collision domain.
2. Broadcast storms.
3. Too much multicast traffic.
4. Low bandwidth.
5. Adding hubs for connectivity to the network.

Question 4

Hubs

Answer 4

Connect network segments together.
Inexpensive way to connect a couple of PC’s together.
Can contribute to congestion on Ethernet network.

Question 5

Routers

Answer 5

1. Connect networks together.
2. Route packets of data from one network to another.
3. Breakup broadcast domains by default.

Question 6

Broadcast Domain

Answer 6

The set of all devices on a network segment that hear all the broadcasts sent on that segment.

Question 7

What are the two advantages of routers in a network?

Answer 7

1. They don’t forward broadcasts by default.

2. They can filter the network based on Layer 3 (Network Layer) information such as IP address.

Question 8

What are the four router functions in a network?

Answer 8

1. Packet switching
2. Packet filtering
3. Internetworking communication
4. Path selection

Question 9

Internetworking

Answer 9

When routers connect two or more networks and use logical IP addressing.

Question 10

Routing Table Map

Answer 10

Used by routers to make path selections and to forward packets to remote networks.

Question 11

Switches

Answer 11

Used to add functionality to a network LAN.
Make LANs work better - to optimize it performance - providing more bandwidth for the LAN users.
Breakup collision domains by default.

Question 12

Collision Domain

Answer 12

An Ethernet term used to describe a network scenario wherein one particular device sends a packet on a network segment at the same time another device on a network sends one. at his results in a collision forcing both devices to retransmit at different times.

Question 13

Bridging

Answer 13

Reduces collisions within a broadcast domain.
Increases number of collision domains on a network.
Provides more bandwidth for users.

Question 14

What are some advantages of using the OSI model?

Answer 14

1. It divides the network communication process into smaller and simpler components, this aids in component development, design and troubleshooting.
2. It allows multiple-vendor development through standardization of network components.
3. It encourages industry standardization by defining what functions occur at each layer of the model.
4. It allows various types of network hardware and software to communicate.
5. It prevents changes in one layer from affecting other layers so development is not hampered.

Question 15

What is the purpose of the upper layers of the OSI?

Answer 15

The top three layers define how the applications within the end stations will communicate with each other and with the end user.

Question 16

What is the purpose of the bottom four layers of the OSI?

Answer 16

They define how data is transmitted end to end.

Question 17

What network devices operate at ALL seven layers of the OSI?

Answer 17

Network Management Stations (NMSs)
Web and Application Servers
Gateways (not default gateways)
Network hosts

Question 18

Application Layer

Answer 18

Layer 7

File, print, message, database, and application services.

Question 19

Presentation Layer

Answer 19

Layer 6

Data encryption, compression, and translation services.

Question 20

Session Layer

Answer 20

Layer 5

Dialog control

Question 21

Transport Layer

Answer 21

Layer 4

End-to-end connection

Question 22

Network Layer

Answer 22

Layer 3
Routing
Manages device addressing
Tracks the location of devices on the network
Determines the best way to move data
Transports traffic between devices that aren’t locally attached.

Question 23

Data Link Layer

Answer 23

Layer 2
Framing
1. Provides the physical transmission of the data and handles error notification, network topology, and flow control.

2. Ensures that messages are delivered to the proper device on a LAN using hardware addresses and will translate messages from the Network layer into bits for the Physical layer to transmit.
3. Responsible for the actual unique identification of each device that resides on a local network.

Question 24

Physical Layer

Answer 24

Layer 1

Physical Topology

Question 25

Six Things to Know About Routers

Answer 25

1. By default they will not forward broadcast or multicast packets
2. They use the logical address in a Network layer header to determine the next hop router to forward the packet to
3. Can use access lists, created by an administrator, to control security on the types of packets that are allowed to enter or exit an interface.
4. Provide Layer 2 bridging functions if needed and can simultaneously route through the same interface.
5. Layer 3 devices provide connections between virtual LANs(VLANs)
6. Can provide quality of service (QoS) for specific types of network traffic.