WGU C172 Network and Security - Foundations; PA and OA set***

It is a network of users that share computer resources in a limited area.

LAN

Local Area Network

LAN

How are Local Area Networks defined?

In terms of protocol and the topology used for accessing the network.

A set of rules established for users to exchange information

Protocol

The network architecture used to interconnect the networking equipment.

Topology

What are the most common topologies for LANs?

Ring, Bus, and Star

Uses a token that is placed in the data channel and circulates around the ring.

Token Ring topology

A deterministic network

Token Ring Topology

Each station connected to the network ensures access for transmission of its messages at regular or fixed time intervals

Deterministic

What are the disadvantages of the Token Ring system?

1. If an error changes the token pattern, it can cause the token to stop circulating.

What is a disadvantage of the Token Ring system from the troubleshooting and maintenance?

The token ring path must be temporarily broken or interrupted if a computer or any device on the network is to be removed or added to the network.

What is a solution to the troubleshooting and maintenance disadvantages of the Token Ring system?

Connect each computer or device on the network to a central token ring hub.

A device that manages the passing of the token instead of relying on individual computers to pass it.

Token ring hub

How does the token ring hub improve the network?

It improves the reliability of the network.

Topology whereas the computers share the media or coaxial cable for data transmission.

Bus topology

The coaxial cable that is looped through each networking device to transmit data in a bus topology

ThinNet

In this topology, all devices on the network can see each other's data traffic.

Bus topology

Topology whereas each computer must wait for pauses in transmission or until the transmission from one device is complete before initiating a new transmission onto the network.

Bus topology

What are the disadvantages of a bus topology?

"1. Data can be corrupted if ore than one device on the network transmits at the same time and will have to be resubmitted.
2. The use of the shared coaxial cable prevents data transmission from being very bandwidth-efficient."

Which topology is seldomly used in modern networks?

Bus topology

What is the most common topology used in today's LANs?

Star topology

Topology that uses twisted-pair cables with modular plugs to connect computers and other networking devices.

Star topology

Topology whereas each device is connected to a switch or hub

Star

A switch or hub facilitates the transfer of data between networking devices in this topology

star

Transmits data to all the devices connected in the star network

hub

Also called a multiport repeater

hub

Not meant for large networks, but are still used in some smaller, slower speed LANs

hub

A transmission from a hub in a star network to all the devices in the network connected to the hub

broadcast

Stores the hardware or physical address for each device connected to its ports in a star network

switch

Sends data transmissions directly to the port of the destination device on the network

switch

The physical input/output interfaces to the networking hardware

port

Where the cables physically connect to each other or a central switch or hub

Port

Only the intended destination device on this network will see the data traffic

star

What is an advantage of the star topology?

It improves the efficiency of the available bandwidth of the network

What is an advantage of the star topology from the troubleshooting and maintenance?

A device can be removed or added without disrupting other devices on the network

All devices are connected to each other

mesh topology

What is an advantage of the mesh network?

It provides full redundancy in the network data paths

What is a disadvantage of the mesh network?

The additional data paths increase the cabling cost and the network hardware cost. It is also very complex.

What type of applications is the mesh topology suited for?

high-reliability applications

What type of applications is the mesh topology not suited for?

general networking applications

Open systems interconnect reference model

OSI

Who was the OSI model developed by?

The International Organization for Standardization

What year was the OSI model developed?

1984

What is the purpose of the OSI model?

to enable different types of networks to be linked together

What is OSI meant for?

To provide a framework for networking devices that ensure compatibility in the network hardware and software.

What is the OSI model meant to accelerate?

The development of new networking technologies.

What is layer 1 of the OSI model?

Physical

The layer of the OSI model that provides the electrical and mechanical connection to the network.

physical

UTP, fiber, and network interface cards are examples of which layer of the OSI model?

physicaL

What is layer 2 of the OSI model?

Data link

Layer of the OSI model that handles error recovery, flow control (synchronization), and sequencing (which terminals are sending and which are receiving)

data link

Also called the media access control layer

data Link

The layer of the OSI model where the Media Access Control or MAC, addressing is defined

data lInk

Where is the Ethernet 802.3 standard defined?

In the MAC or media access control

Also called the Ethernet address

MAC or media access control

MAC addresses are an example of which layer of the OSI model?

data linK

What is layer 3 of the OSI model?

Network

layer of the OSI model that accepts outgoing messages and combines messages or segments into packets, adding a header that includes routing information.

network

Acts as the network controller

network layer of the OSI model

Internet Protocol (IP) and internetwork packet exchange (IPX) are examples of which layer of the OSI model?

networK

What is layer 4 of the OSI model?

Transport

layer of the OSI model that is concerned with message integrity between source and destination

transport

layer of the osi model that also segments/reassembles the packes and handles flow control

tRansport

Transmission control protocol (TCP) and User Datagram Protocol are examples of which layer of the OSI model?

transporT

What is layer 5 of the osi model?

Session

layer of the osi model that provides the control functions necessary to establish, manage, and terminate the connections as required to satisfy the user request

session

Network File system (NFS) and Structured Query Language (SQL) are examples of which osi model layer?

sessioN

What is layer 6 of the osi model?

Presentation

layer of the osi model that accepts and structures the messages for the application. If necessary, it will translate one code to another

presentation

layer of the osi model that is also responsible for data compression and encryption

pResentation

American Standard Code for Information Interchange (ASCII) and Joint Photographic Experts Group (JPEG) are examples of which layer of the OSI model?

presentatioN

What is layer 7 of the osi model?

Application

layer of the osi model that interacts with application programs that incorporate a communication component such as your internet browser and email

application

layer of the osi model that is also responsible for logging the message in, interpreting the request, and determining what information is needed to support the request

aPplication

Hypertext Transfer Protocol (HTTP) for web browsing, File Transfer Protocol (FTP) for transferring files, and Simple Mail Transfer Protocol (SMTP) for email transmission are examples of which osi model layer?

applicatioN

What is step one of the three basic steps in the process of isolating a network problem?

Is the connection to the machine down (layer 1)

What is step two of the three basic steps in the process of isolating a network problem?

Is the network down? layer 3

What is step three of the three basic steps in the process of isolating a network problem?

Is a service on a specific machine down? layer 7

A reply from" response from a ping indicates whate?"

A connection to the server is up

A request timed out" response from a ping indicates what?"

the network connection is down

What is the function of the data link layer of the osi model?

to provide for the flow of data MAC addresses

What is the function of the network layer?

to provide routing decisions IP, IPX

What is the function of the transport layer of the osi model?

to ensure error free packets

What is the function of the session layer of the osi model?

to establish, manage, and terminate NFS, SQL sessions

What is the function of the presentation layer of the osi model?

to ensure protocol conversion, data transactions ASCII, JPEG

What is function of the application layer of the osi model?

to support applications HTTP, FTP, and SMTP(email)

Which networking protocol is used in most modern computer networks?

Ethernet

A carrier sense multiple access with collision detection protocol for local area networks

Ethernet

Must have the capability to detect data collisions (collision detection) to avoid two or more computers from attempting to broadcast a message at the same time.

Ethernet systems

Provide grouping of information for transmission

packet

What does the header of a packet consist of?

The preamble, start frame delimiter, destination and source addresses, and length/type field

Preamble, start frame delimiter, destination mac address, source address, length/type, data, pad, and frame check sequence.

The structure of the Ethernet frame

An alternating pattern of 1s and 0s used for synchronization

The preamble of an Ethernet packet

A binary 8 bit sequence of 10101011 that indicates the start of the frame

The start frame delimiter of an Ethernet packet

The MAC address associated with the network adapter or Ethernet network interface card (NIC)

The destination and source MAC addresses of an Ethernet packet

An indication of the number of bytes in the data field if this value is less than 1500, or if the number is greater than 1500, and indication of the type of data format such as IP and IPX

The length/type of the Ethernet packet frame

The variable length of data being transferred from the source to the destiontion

The data of the Ethernet packet frame

A field used to bring the total number of bytes up to the minimum of 46 if the data field is less than 46 bytes

The pad of the Ethernet packet frame

A 4 byte CRC value used for error detection

The frame check sequence of the Ethernet packet frame

What is the minimum length of the Ethernet frame from destination MAC address through the frame check sequence?

64 bytes