Light Study Pack

Question 1

What is a SQL Injection?

Answer 1

SQL injection a specific type of injection attack that targets databases to execute malicious SQL commands

Question 2

What are Zero-Day Exploits?

Answer 2

Zero-day attacks target software vulnerabilities that are unknown to the software vendor and have no patch available yet.

Question 3

What are Password Attacks?

Answer 3

Password attacks attempt to gain unauthorized access by guessing passwords, using keyloggers to capture keystrokes, or using other methods to crack credentials

Question 4

What is an .iso file?

Answer 4

A disk image that contains an exact copy of the contents of a storage device, typically an optical disc such as a CD or DVD. It is commonly used for distributing software, operating systems, and other large datasets and can be mounted as a virtual disk for installation or access

Question 5

How does trunking work?

Answer 5

Trunking carries traffic for multiple VLANs using tagging (IEEE 802.1Q). It’s primarily a switch-to-switch connection

Question 6

What’s a native VLAN?

Answer 6

Native vLAN the untagged VLAN on a trunk port — typically VLAN 1, and the best practice is to change it.

Question 7

Devices not joining the network after VLAN change.

Answer 7

TheVLAN is not assigned, or DHCP scope doesn’t include that VLAN’s subnet.

Question 8

What is an internal switch in Hyper-V?

Answer 8

A type of virtual switch that allows communication between virtual machines on the same host while remaining isolated from the external network.

Question 9

What does “Enable virtual LAN identification” do in Hyper-V?

Answer 9

Enabling VLAN identification allows the VM to tag outgoing network frames with a VLAN identifier, facilitating communication within a specific VLAN.

This configuration is useful when working with Virtual Local Area Networks (VLANs) to logically segment network traffic within a virtualized environment

Question 10

Difference between Link Aggregation Control Protocol (LACP) and Port Aggregation Protocol (PAgP)?

Answer 10

LACP (IEEE standard) and PAgP (Cisco proprietary) both combine the bandwidth of multiple physical ports into a single logical port.

They also negotiate EtherChannel formation

The difference is that LACP is IEEE standard and PAgP is Cisco proprietary

Question 11

What’s Port Security?

Answer 11

Port security limits which MAC addresses can connect to a switch port to reduce unauthorized access.

Question 12

Why enable Bridge Protocol Data Units (BPDU) Guard?

Answer 12

BPDU disables ports receiving unexpected STP messages — protecting against rogue switches.

Question 13

What causes a “link light” notification but there’s no connectivity?

Answer 13

Duplex mismatch | vLAN misconfiguration | wrong port assignment

Question 14

Intermittent connectivity for one PC?

Answer 14

Possibly a:

• bad cable
• patch port
• NIC

— swap components to isolate.

Question 15

Slow network response after upgrade?

Answer 15

Duplex mismatch or switch port misconfiguration — check for auto/forced negotiation.

Question 16

What tool checks for cable breaks or length?

Answer 16

A Time Domain Reflectometer (TDR) for copper or Optical TDR (OTDR) for fiber.

Question 17

What’s attenuation?

Answer 17

Signal loss over distance or poor-quality cable — often fixed with shorter runs or better cable.

Question 18

What’s the effect of near-end crosstalk (NEXT)?

Answer 18

Reduced signal quality — usually caused by improper twists or cable damage.

Question 19

How to fix No Link on a copper cable?

Answer 19

• Check pins
• Verify crimps
• Confirm whether straight-thru or crossover cable is appropriate

Question 20

When do you use a cable certifier?

Answer 20

To validate that installed cabling meets specifications and supports the desired speed.

Question 21

Users get 169.254.x.x addresses — what’s wrong?

Answer 21

DHCP server unreachable or scope exhausted. The OS assigns APIPA automatically.

Question 22

What are the APIPA IP addresses for IPv4 and IPv6 referred to as?

Answer 22

They are Link-Local addresses that are automatically generated by a host device

Question 23

What does the ping test do?

Answer 23

Layer 3 IP connectivity — basic reachability using ICMP Echo Request/Reply.

Question 24

Users can ping IPs but not hostnames.

Answer 24

DNS resolution issue — check DNS server configuration or client settings.

Question 25

Web traffic blocked but ping works.

Answer 25

Layer 4–7 issue: * Check firewall * Check proxy * **DNS filtering likely**

Question 26

When would you use ipconfig or ifconfig?

Answer 26

To ***view or renew IP configuration*** on a host. ## Footnote ifconfig command is for Linux systems

Question 27

What’s traceroute used for?

Answer 27

***Maps the path*** packets take and identifies routing or latency issues.

Question 28

What’s netstat good for?

Answer 28

***Displays open ports and active connections*** — useful for identifying unwanted traffic.

Question 29

What’s nmap used for?

Answer 29

***Scans*** *devices or networks to identify open ports, OS types, and active hosts*

Question 30

What does Wireshark do?

Answer 30

***Captures and analyzes network packets*** — best for detailed protocol-level troubleshooting.

Question 31

CSMA/***CA*** vs. CSMA/***CD***

Answer 31

Question 32

What are some step-by-step Network-level troubleshooting tips?

Answer 32

Question 33

What are some methods of traffic shaping?

Answer 33

* Packet scheduling * Rate limit/ Policing * Traffic classification * Buffers and Ques

Question 34

**Packet scheduling** (traffic shaping method)

Answer 34

* Determines which packets are sent first. [Examples]: Weighted Fair Queuing (WFQ) Priority Queuing

Question 35

**Rate limiting/ policing** (traffic shaping method)

Answer 35

* Restricts traffic to a specific bandwidth. * Excess packets can be dropped or delayed

Question 36

**Traffic classification** (traffic shaping method)

Answer 36

* Identifies traffic by protocol, port, IP, or application. * Enables granular control for shaping or prioritizing traffic

Question 37

**Buffers and Ques** (traffic shaping method)

Answer 37

* Temporarily store packets during congestion. * Can delay lower-priority packets while allowing high-priority traffic to pass

Question 38

What is Maximum Transmission Unit (MTU)?

Answer 38

***The biggest data packet size, in bytes, that may be sent over a network***. MTU enables the efficiency of transmitting data and is crucial for preventing fragmentation issues. ## Footnote Proper MTU configuration ensures that data is transmitted optimally and without the need for packet fragmentation, contributing to network performance and reliability

Question 39

What does modifying the MTU involve?

Answer 39

***Adjusting the maximum size of data packets that can be transmitted over a network*** is done to optimize network performance or accommodate specific network requirements. ## Footnote Reasons for modifying MTU include **reducing latency, improving bandwidth efficiency, and ensuring compatibility** with network devices that support non-standard MTU values.

Question 40

What is the difference between scalability and elasticity in cloud computing?

Answer 40

***Scalability*** refers to a system's ability to handle increased workloads by adding resources, typically through vertical scaling (upgrading existing hardware) or horizontal scaling (adding more machines) ***Elasticity*** is the capability of a cloud system to automatically and dynamically adjust resources in response to real-time changes in demand. ## Footnote Scalability focuses on the system's capacity to grow over time, while elasticity emphasizes immediate, automated adaptation to fluctuating workloads