Notes, summaries, assignments, exams, and exercises for Computer science for Vocational training

Computer System Components and Definitions

Perform = realizar || Word processor = procesador de textos || Built-in = incorporado || Store = tienda || Financial = financiero

Keep, save = mantener, guardar || Execute, do = ejecutar, hacer || Monetary = monetario || Connected to the internet = conectado a internet || Program used for text manipulation = programa para manipular texto || Copy files from a server to your PC or mobile = copiar archivos de un servidor a PC o móvil

Perform operations = realizar operaciones || Do research = hacer la investigación || Carry out transactions = llevar a cabo transacciones

Monitor = monitor || Keyboard = teclado || Printer = impresora || Scanner = escáner || Speakers = altavoces || Fan = ventilador || Processor

RHQ Configuration

Hostname: rhq

Username: isp

Password: 0 duocuc

Interface Configuration

FastEthernet0/0

• IP Address: 172.31.0.1 255.255.0.0
• IP NAT Inside
• Duplex: Auto
• Speed: Auto

Serial0/0/0

• No IP Address
• Encapsulation: Frame-Relay

Serial0/0/0.100 (Point-to-Point)

• Bandwidth: 512
• IP Address: 10.10.0.1 255.255.0.0
• Frame-Relay Interface-DLCI: 100
• IP OSPF Authentication: Message-Digest
• IP OSPF Message-Digest-Key: 1 MD5 cisco
• IP NAT Inside

Serial0/0/0.200 (Point-to-Point)

• Bandwidth: 512
• IP Address: 10.11.0.1 255.255.0.0
• Frame-Relay Interface-DLCI: 200
• IP OSPF Authentication: Message-Digest
• IP OSPF Message-Digest-Key: 2 MD5 cisco
• IP NAT Inside

Serial0/0/1

• IP Address: 200.10.10.2 255.255.255.0
• Encapsulation: PPP
• PPP Authentication: CHAP
• IP NAT Outside

Routing Configuration

Router...

Database Presentation and Form Generation

Systems present data on a screen or printer using a predefined format, or one that is easy to define without requiring knowledge of database languages or programming. This includes form generators and dialogues that display items, allowing for information input via keyboard or buttons.

Data Structure Diagrams

A Data Structure Diagram is a graphic used to represent the design of a database. It utilizes boxes to represent nodes and lines to represent ties or relations, specifying the general logical structure of the database.

Key Terminology

• Path: Lines that connect nodes.
• Segment: A record of a hierarchical database.
• Member: A child record in a networked database.
• Joint: A connection between two record types

Biometric Systems: Enhancing Security

Biometric systems, applied to information systems, allow for the authentication of individuals using electronic technologies. These technologies employ complex mathematical formulas to ensure that the person applying for entry to a resource, or a physical space, is who they claim to be.

Increased Security with Biometric Access Systems

Personal identification methods to control access are based on:

• Something you know: passwords or access keywords.
• Something you own: for example, an encoded magnetic card.
• A personal characteristic: such as fingerprints or iris.

Combining two or more methods provides an even higher level of security.

Biometrics: Key Characteristics

• Universality: All individuals possess this characteristic.

Essential System Maintenance Tools

System Utilities for Performance

• Defragmenter: Defragments disk volumes to optimize file storage and access speed.
• Scandisk (Check Disk): Scans, detects, and repairs errors in the file system and hardware on your hard drive.
• Disk Cleanup: Helps free up disk space by searching for and removing unnecessary files, temporary files, and Internet cache files.
• System Information: Collects and displays detailed system data, crucial for diagnosing hardware and software problems.

Data Protection and Backup

Backup: Creating copies of critical data stored on the computer that you wish to preserve.

Methods of Protection:

• Firewall: Acts as a security barrier between your PC and the network, controlling incoming and outgoing traffic.

Storage Devices

Storage Devices: devices that store information. They comprise:

Magnetic Disks

Magnetic disks: Hard drives, floppy disks have large capacity, non-volatile random access, but live slower. It is a closed box, partly comprising:

• Platters: Stored information resides here.
• Head: Reads and writes on the platters.
• Motors: Spin the platters and move the heads.

Components of Magnetic Disks

Platters: Glass, ceramic, or aluminum; joined by a shaft and a motor to rotate at 3600 and 7200 rpm, with a diameter of 5.5 inches.

Heads: Magnetic sensor that reads the charge and a magnet to change the charges for writing.

Spindle (Topic): Support for the disks.

Actuator: The motor that moves the heads.

Structure and Organization

Tracks (Structure-Runs): Concentric...

Computer Hardware and Software Components

Software: Programs and Operating Systems

The machine consists of hardware capable of performing a variety of tasks. Electronic computer components need software to run. The programs will help us process information. A set of orders and instructions constitutes a program. A single program or a set of programs is a software application. We need to keep an operating system running, which allows software to process information using physical components.

Software Categories

• Operating system — manages hardware and provides services for applications.
• Application software — processes personal and end-user information.

Physical Components (Hardware)

Physical components include:

1. CPU (Central Processing Unit) —

Understanding Network Protocol Families

While the OSI model defines a comprehensive reference for network study, not every commercial network fully adopts OSI designs. Instead, many networks are built upon specific technologies and proprietary protocols.

NetWare Family

Manufactured by Novell, NetWare was once among the most widely used network systems worldwide. It was renowned for its high performance and capacity for growth.

NetBEUI Family

Microsoft has developed several operating systems that utilize NetBEUI (NetBIOS Extended User Interface) for communications within local area networks. Originally an IBM protocol introduced in 1985, NetBEUI provides a foundational basis for building peer-to-peer networks.

AppleTalk Family

AppleTalk is the network...

Asynchronous Transfer Mode (ATM) Networks

Integrating Multimedia Services with ATM VPN

The integration of voice and image services within Asynchronous Transfer Mode (ATM) creates a Multimedia Virtual Private Network (VPN). This innovative approach allows services previously provided on separate networks to be consolidated into a single, unified network.

ATM VPNs are based on the concept of a Virtual Private Network, offering resources dedicated exclusively to the client. This is achieved through a shared network infrastructure and a single access point to the network. Integration is facilitated by deploying an integration device at the customer's premises.

ATM Integration Device Capabilities

The integration device can consolidate data, voice, and...

Domain Name System (DNS)

The DNS defines domain addresses (made up of character strings) and converts them to binary transport addresses (IP addresses). It identifies users and computers in the network using DNS server names.

DNS is composed of a distributed database (DB) on the network. Its tables contain correspondence between domain names and IP addresses.

Types of DNS Servers

• Cache Server

  Saves name information on domains, not zones.

• Primary Server

  Obtains information for its zones from its zone files. If data needs modification in a zone, it is done on the primary server. It is undesirable to have only a single primary server, as its failure may prevent resolving requests.

• Secondary Server

  Gets information from the primary server. Secondary servers