Network Interconnection and Topology

Data Encryption, Security and Parity

1. Describe how Parity error checking works.

way to ensure that the data is transmitted correctly is to use parity bits, which involves keeping track of the number of 1’s and 0’s the data should contain.

1. Given the following table, indicate what the proper parity bit is using even parity.

1. Describe Private-Key encryption

In private-key encryption the sender and receiver both have the same key. They must keep this key private from outsiders to retain security of the message. The sender encrypts the message with the same key that the receiver uses to decrypt the message.

1. Describe Public �Key encryption

Public-key encryption has two separate keys. The receiver has a key that he gives to all who wish to send him an encrypted message. This is the public key. The only key that can decrypt the message is the private key, which the recipient has; this key should be secreted away (hence private key).

1. Using the Passphrase CAT, decrypt the following word: VVHVICQF

1. Explain plaintext and ciphertext.

Plaintext is the message before encoding or after decoding. It is readable text.

Ciphertext is the message after the plaintext has been encoded by the encryption algorithm. This text is not understandable in its current form.

1. If a computer is connected to the internet, what precautions should be taken to protect against malicious access to the machine.

Firewall protects a computer system, by always denying network communications requests that the user has not predefined as permissible.

1. Define a virus and how it harms a computer.

file virus -virus hidden in an application program. When the program is executed, the virus replicates itself and can perform malicious activities now or later.

macro virus - virus hidden in a document type that supports macros or scripts, such as Word or Excel. Opening the document can cause the macro to execute immediately.

boot sector virus - virus in the boot sector of the disk or floppy. It spreads every time the infected disk is in the computer when it boots.

1. Define a Trojan horse and how it harms a computer

Trojan horse - computer program that appears to perform one function while actually performing another.

1. Define a Worm and how it harms a computer.

Worm- program that gains access to a computer, typically through a network security flaw, or another opening caused by careless system administration. The worm then attempts to access additional computer systems. It may have a payload or simply clog up the computer.

Data Communication

1.FQDM (Specify what every segment of www.icarnegie.com represents.)

Fully-qualified domain name contains a machine, domain, and top-level domain designation. From this common name structure an IP address can be referenced and the machine connected to.

2.DNS (Describe the acronym as well as what a DNS does.)

The function of the DNS is to translate common names, as www.icarnegie.com, to Internet names, 204.194.30.130, that are represented by IP addresses

3.IP Address (What is an IP Address? How long is an IP Address? How is it normally represented?)

IP-Internet Protocol specifies the format of packets also called dataprograms and the addressing scheme

4.TCP / IP (Explain the Acronym. What is it used for?)

TCP-transmission control protocols, enables two hosts establish a connection and exchangestreams of data

5.MAC Address (What is a MAC Address? What does the MAC address identify? How long is a MAC Address? How is it normally represented?)

A MAC address, or Media Access Control address, is a 48- or 64-bit address associated with a network adapter. While IP addresses are associated with software, MAC addresses are linked to the hardware of network adapters

6.Explain a Packet as it relates to Network communication.

A packet is the smallest unit of data that is sent over a network.

7.List at least three different types of connections used to connect to the internet.

8.Explain Simplex communication.

Simplex communication is mono-directional. There is one sending unit, and at least one receiving unit. As television station is an example of simplex communication

9.Explain Half-Duplex communication.

.Half-duplex communication is a bidirectional form of communication, in which any given point (system) can either send or receive data at any given time, but not do both. CB radio is an example of half-duplex communication. Half-duplex communication may have collisions.

10. Explain Full-Duplex communication

Full-duplex communications allows any device to both send and receive data at the same time. A telephone is an example of full-duplex communication.

Networking Devices

Describe in detail the function of the following network devices:

1. NIC –network identify card,
2. Hub-10 -100MB/Sec Networks using a Star topology require a central point for the devices to connect
3. Gateway- A gateway is a device used to connect networks using different protocols.
4. Router- A router connects pieces of a network and directs network traffic on the basis of their IP addresses.
5. Switch- Switches are a special type of hub that offers an additional layer of intelligence to basic, physical-layer repeater hubs.
6. Bridge- a bridge is used to join two network segments together, it allows computers on either segment to access resources on the other.
7. Server- A server is a system that responds to requests across a computer network to provide, or help to provide, a network service.
8. Workstation- a workstation is a computer designed for technical or scientific applications.
9. Thin Client-Network application in which the client does very little processing and the network server does most of the work.
10. Thick Client Network application in which the client does relatively significant processing, and the network server does more simple tasks.

Backup and Restore

Explain :

1. Full Backup - dates all files in the backup set
2. Incremental Backup- dates backup datas all files modified since the last backup .
3. Differential Backup- dates all files modified since the last full backup
4. What is the purpose of RAID? Controller and at least two hard
5. Assume that you are asked to create a backup procedure for data backup in a situation where loss prevention is crucial, but space considerations are also necessary. Describe an acceptable weekly backup procedure of full, incremental or differential backups that would assure the ability to recover all of the data.
6. Given the scenario in Question number 5, suppose a catastrophic failure occurs on Thursday. Describe the process to restore the data, given your backup solution.

Network Interconnection and Topology

Date: 2015-12-18; view: 1061