Help Desk pt 2

IT Help Desk

Provides technical support to users by troubleshooting hardware, software, and network issues

Ticket

A record of a user's issue or request that IT tracks until resolution

SLA

Service Level Agreement; defines expected response and resolution times

Escalation

Forwarding a problem to a higher-level technician when additional expertise is needed

Troubleshooting Process

Identify the problem, establish a theory, test the theory, create a plan, implement the solution, verify functionality, document findings

IP Address

A unique address used to identify a device on a network

IPv4

32-bit IP addressing system (example: 192.168.1.1)

IPv6

128-bit IP addressing system designed to replace IPv4

Subnet Mask

Determines which portion of an IP address identifies the network and host

Default Gateway

The router used to reach devices outside the local network

DNS

Domain Name System; translates domain names into IP addresses

DHCP

Dynamic Host Configuration Protocol; automatically assigns IP addresses and network settings

MAC Address

A unique physical hardware address assigned to a network interface card

LAN

Local Area Network; connects devices within a limited area

WAN

Wide Area Network; connects networks over large geographic areas

VPN

Virtual Private Network; creates a secure encrypted connection over the internet

TCP

Transmission Control Protocol; reliable, connection-oriented communication

UDP

User Datagram Protocol; fast, connectionless communication

Three-Way Handshake

TCP connection process: SYN, SYN-ACK, ACK

HTTP

Hypertext Transfer Protocol; used for web traffic

HTTPS

Hypertext Transfer Protocol Secure; encrypted web traffic using SSL/TLS

SSL

Secure Sockets Layer; older encryption protocol

TLS

Transport Layer Security; modern encryption protocol replacing SSL

FTP

File Transfer Protocol; transfers files between systems

SFTP

Secure File Transfer Protocol; encrypted file transfers

SMTP

Simple Mail Transfer Protocol; sends email

POP3

Post Office Protocol Version 3; downloads email to a device

IMAP

Internet Message Access Protocol; synchronizes email across devices

RDP

Remote Desktop Protocol; remotely controls another computer

SSH

Secure Shell; encrypted remote command-line access

TCP/IP

The protocol suite used for internet communication

OSI Model

A seven-layer networking reference model

Layer 1 Physical

Cables, hubs, signals, and physical transmission

Layer 2 Data Link

MAC addresses, switches, frames

Layer 3 Network

IP addresses and routing

Layer 4 Transport

TCP and UDP communication

Layer 5 Session

Establishes and manages communication sessions

Layer 6 Presentation

Data formatting, compression, and encryption

Layer 7 Application

User-facing protocols such as HTTP, HTTPS, DNS, and FTP

TCP/IP Application Layer

Provides network services to applications

TCP/IP Transport Layer

Uses TCP or UDP for communication

TCP/IP Internet Layer

Uses IP for routing and addressing

TCP/IP Network Access Layer

Handles physical network communication

Ping

Tests connectivity between devices

Tracert

Shows the path packets take to a destination

Nslookup

Queries DNS to translate domain names to IP addresses; helps troubleshoot DNS issues

Ipconfig

Displays network configuration information

Netstat

Shows active network connections and listening ports

Tasklist

Displays running processes

SFC

System File Checker; scans and repairs Windows system files

BSOD

Blue Screen of Death; critical Windows error

MFA

Multi-Factor Authentication; requires multiple forms of verification

Malware

Malicious software designed to harm systems

Phishing

Fraudulent attempt to steal information through deceptive messages

Ransomware

Malware that encrypts files and demands payment

Firewall

A security device or software that filters network traffic

Antivirus

Software that detects and removes malware

Patch

A software update that fixes bugs or security vulnerabilities

Active Directory

Microsoft directory service used to manage users, computers, and resources

AD

Abbreviation for Active Directory

Domain

A group of computers and users managed centrally through Active Directory

Group Policy

Settings used to manage users and computers in Active Directory

Ticket Priority

Classification indicating how urgent an issue is

Knowledge Base

A collection of documentation and solutions used by support teams

CIA Triad

Confidentiality, Integrity, Availability

Confidentiality

Making sure information is only accessible to authorized people (passwords, MFA, Encryption)

Integrity

Ensuring data remains accurate, trustworthy, and unchanged unless modified by authorized users (Hashing, Checksums, File permission, Digital signatures, Version control)

Availability

Making sure systems, networks, and data are accessible when needed (Backups, Redundant servers, Load balancing)