Typical Interview Questions Asked for Network Analyst Roles

1

How do VLANs improve security and performance?

Reference answer

A VLAN (Virtual Local Area Network) logically divides a single physical network into multiple broadcast domains. This allows you to group devices together regardless of their physical location. This segregation enhances both security and performance. VLANs improve security by isolating network traffic. For instance, you can separate traffic from different departments (e.g., finance, engineering) or types of devices (e.g., employee computers, IoT devices). This prevents unauthorized access to sensitive data. If one VLAN is compromised, the impact is limited to that specific VLAN, reducing the overall risk. VLANs also improve performance by reducing broadcast traffic within each segment. Since broadcasts are confined to their respective VLAN, less bandwidth is consumed, and network congestion is minimized. This leads to faster data transmission and better network responsiveness.

2

What is ARP?

Reference answer

Address Resolution Protocol (ARP) maps IP addresses to MAC addresses in Layer 2 communications. - Uses ARP requests and replies. - Entries are stored in the ARP table.

3

Explain the difference between a Name Server and a DNS Server.

Reference answer

Let's use the following example — Scenario: Resolving the Domain “lightrun.com”. - User Query: A user types “lightrun.com” into their browser. - Recursive Resolver (DNS Server): The user's device sends a query to a recursive resolver (a DNS server) provided by their ISP or a public DNS service like Google Public DNS (8.8.8.8) or Cloudflare DNS (1.1.1.1). - Root DNS Server: The recursive resolver queries a root DNS server. The root DNS server doesn't know the IP address of “lightrun.com” but knows which TLD DNS server to ask. It directs the resolver to the .com TLD DNS server. - TLD DNS Server: The recursive resolver then queries the .com TLD DNS server. The TLD server also doesn't have the exact IP address but knows the authoritative nameservers for “lightrun.com.” It responds with the nameservers responsible for “lightrun.com”, such as ainsley.ns.cloudflare.com and art.ns.cloudflare.com. - Authoritative Nameservers: Finally, the recursive resolver queries one of the authoritative nameservers for “lightrun.com”. These nameservers are specifically designated to hold the DNS records for the domain “lightrun.com”. The authoritative nameserver responds with the IP address associated with “lightrun.com”. - Response to User: The recursive resolver sends the IP address back to the user's device, which can now connect to the web server hosting “lightrun.com” using that IP address. Key Differences Illustrated Recursive Resolver (DNS Server): - Role: Handles the entire process of resolving a domain name by querying multiple DNS servers in sequence. - Example: The DNS server at 8.8.8.8 (Google Public DNS) or 1.1.1.1 (Cloudflare DNS). - Function: Queries root servers, TLD servers, and authoritative nameservers to resolve the domain name on behalf of the user. Authoritative Nameserver: - Role: Holds and serves the DNS records for specific domains and responds with authoritative answers. - Example: ainsley.ns.cloudflare.com and art.ns.cloudflare.com for “lightrun.com.” - Function: Directly provides the IP address for “lightrun.com” when queried by a recursive resolver.

4

What is a firewall and what are its types?

Reference answer

A firewall is a network security device or software that monitors and controls incoming and outgoing network traffic based on predetermined security rules. Types of firewalls include: ● Packet-Filtering Firewalls: Inspect packets at the network layer and allow or block them based on rules. ● Stateful Inspection Firewalls: Track the state of active connections and make decisions based on the context of traffic. ● Proxy Firewalls: Intercept and filter requests by acting as an intermediary between users and the internet. ● Next-Generation Firewalls (NGFW): Combine traditional firewall features with advanced threat detection capabilities.

5

What is the ping command and how is it used?

Reference answer

The ping command is a simple yet powerful tool used in networking to troubleshoot issues related to network connectivity. The core function of ping is to send a signal, known as an Internet Control Message Protocol (ICMP) echo request, from one device to another over a network or the internet. When the other device receives the echo request, it sends back an echo reply. Checking for these replies helps you determine whether or not the two devices can communicate with each other and how long this process takes, which is known as latency. If the ping is successful and you get a reply, then it means the pathway between the devices is clear. If you don't receive a reply, it can indicate a network issue such as packet loss or a problem with the other device. The ping command can give you insight into the quality of a network connection or help you diagnose and pinpoint network problems. For example, high latency or loss of ping packets can indicate network congestion, faulty hardware, or configuration issues. So it's an extremely useful tool for network troubleshooting and performance measurement.

6

Explain the difference between HTTP, HTTPs, TCP, UDP and gRPC.

Reference answer

No answer provided in the content.

7

What are common network security threats and how can they be mitigated?

Reference answer

Network security threats come in various forms. Malware (viruses, worms, ransomware, Trojans) infects systems to steal data, disrupt operations, or demand ransom. Mitigation involves anti-malware software, regular system scans, and user education. Phishing attacks use deceptive emails or websites to trick users into revealing sensitive information; mitigation includes employee training to recognize phishing attempts, strong email filters, and multi-factor authentication. Denial-of-Service (DoS) and Distributed Denial-of-Service (DDoS) attacks overwhelm a system with traffic, making it unavailable. Mitigation includes traffic filtering, rate limiting, and using DDoS protection services. Man-in-the-Middle (MitM) attacks intercept communication between two parties; mitigation includes using encryption (HTTPS), VPNs, and secure Wi-Fi. Other threats include SQL injection (mitigated by input validation and parameterized queries), cross-site scripting (XSS) (mitigated by output encoding and input validation), and brute-force attacks (mitigated by strong passwords, account lockout policies, and multi-factor authentication). Regular security audits, penetration testing, and keeping systems updated with the latest security patches are crucial for overall network security.

8

What is SLIP?

Reference answer

SLIP, or Serial Line Interface Protocol, is an old convention created during the early UNIX days. This is one of the conventions that are utilized for distant access in PC network.

9

What is Quality of Service (QoS) and how does it work?

Reference answer

Quality of Service (QoS) is a set of techniques used to prioritize different types of network traffic, ensuring optimal performance for critical applications. It works by first classifying traffic based on criteria like source/destination IP, port numbers, or application type. Packets are then marked with a QoS value. Mechanisms like queuing (different queues for different traffic types), scheduling (prioritizing certain queues), and shaping (controlling the rate of traffic) are used to allocate bandwidth and prioritize important traffic flows. This minimizes latency and jitter for real-time applications like voice and video, while ensuring other traffic types receive appropriate service.

10

What do you mean by a point to point link?

Reference answer

A point to point link is a connection between two dedicated networking devices. The complete bandwidth of the link is utilized for the transmission of data between two devices. There may be multiple connections between devices. Using a PPP link, two different networks can be connected, where one network will work as the endpoint for another. These days PPP links are created using modems and PSTN (Public Switched Telephone Networks). An example of a PPP link is a telephone call between two people.

11

What is ARP, and What is Its Role?

Reference answer

ARP (Address Resolution Protocol) resolves a 32-bit IP address into a MAC address. In a network, when a device needs to send data to another device, it uses ARP to map the destination's IP address to its physical MAC address.

12

What is the difference between a wireless repeater and a wireless bridge?

Reference answer

- Wireless repeater: Extends the range of a single wireless network, amplifying the signal. - Wireless bridge: Connects two or more separate networks, regardless of whether they are wired or wireless.

13

What is the role of a DNS server in wireless networking?

Reference answer

A DNS (Domain Name System) server translates human-readable domain names (like google.com) into IP addresses (like 172.217.160.142), allowing devices to locate and access websites and other online resources.

14

Tell us a bit about you and your background

Reference answer

This question gives you the opportunity to tell your potential employer a bit about you, from your interests to how you got to where you are in your network engineering career, whether youâre a graduate or senior network engineer. Keep your answer concise without rambling off-topic, and remember itâ€™s important to keep linking back to the role and any previous positions youâ€™ve had within the space that are relevant to the network engineer job youâ€™re applying for.

15

What is Piggybacking in context to Wi-Fi?

Reference answer

Piggybacking is a term which states that something that is riding on the back of something else to complete his/her motive, just like similar to an idiom putting gun to another's shoulder and performing Hunting, so piggybacking is a term used to refer to access of a wireless internet connection by bringing one's own computer within the range of another's wireless connection, and using that service without the subscriber's explicit permission or knowledge. It is a legally and ethically controversial practice, with laws that vary in jurisdictions around the world. Piggybacking is an unauthorized tapping into another's connection with a public utility. For e.g.- So piggybacking can take place like when I am accessing the wireless connection of my neighbour Wi-Fi without his/her knowledge by hacking his static ip address, then it would be possible for me to access the Wi-Fi connection of others.

16

What are the different types of wireless security protocols?

Reference answer

Common wireless security protocols include: - WEP (Wired Equivalent Privacy): An early security protocol, considered weak and easily compromised. - WPA (Wi-Fi Protected Access): Improved security over WEP, offering better encryption and authentication. - WPA2 (Wi-Fi Protected Access 2): Provides stronger encryption using AES (Advanced Encryption Standard) and is the most secure option. - WPA3 (Wi-Fi Protected Access 3): Latest security standard, offering enhanced security features, including more robust authentication and stronger encryption.

17

How much is the distance and data rate supported in WLAN devices?

Reference answer

There are different distances and data rates available in WLAN devices based on the IEEE standard they are supporting.

18

Why Bandwidth is important to network performance parameters?

Reference answer

Bandwidth is characterized as the measure of data or information that can be transmitted in a fixed measure of time. The term can be used in two different contexts with two distinctive estimating values. In the case of digital devices, the bandwidth is measured in bits per second(bps) or bytes per second. In the case of analog devices, the bandwidth is measured in cycles per second, or Hertz (Hz). Bandwidth is only one component of what an individual sees as the speed of a network. True internet speed is actually the amount of data you receive every second and that has a lot to do with latency too.

19

How is Vulnerability Management Conducted?

Reference answer

This includes regular vulnerability scanning, risk assessment, creating remediation plans, and tracking the repair process.

20

What are the different types of network cables and their applications?

Reference answer

There are several types of network cables, each suited for different applications. Ethernet cables, like Cat5e, Cat6, and Cat6a, are commonly used for local area networks (LANs) to connect computers, routers, and switches. They transmit data using electrical signals and are categorized based on their speed and bandwidth capabilities, with Cat6 and Cat6a supporting higher speeds and frequencies than Cat5e. Fiber optic cables transmit data as light pulses, making them ideal for long distances and high-bandwidth applications. They are less susceptible to interference and can support much higher data rates than Ethernet cables. Fiber optic cables are used in wide area networks (WANs), metropolitan area networks (MANs), and in data centers for interconnecting servers and network equipment.

21

What is NFC (Near Field Communication)?

Reference answer

NFC is a short-range wireless communication technology that enables devices to exchange data by bringing them close together, typically used for contactless payments and data transfer.

22

Explain the OSI Seven-Layer Model and its Functions.

Reference answer

The OSI model consists of seven layers: physical, data link, network, transport, session, presentation, and application. Each layer provides specific functions to enable network communication.

23

Define network slicing in the context of 5G.

Reference answer

Network slicing is a game-changing concept in 5G, allowing the creation of virtualised, isolated networks tailored to specific applications. Network slicing in 5G involves partitioning the Network into virtual slices, each customised to meet the unique requirements of different services or applications. This capability enables the efficient coexistence of diverse use cases on a single physical infrastructure.

24

What are the key considerations when designing a network for a high-availability application?

Reference answer

When designing a network for a high-availability application, key considerations revolve around redundancy, fault tolerance, and monitoring. Redundancy is crucial at every level: multiple network paths, redundant network devices (routers, switches, firewalls), and load balancing across multiple servers. This ensures that if one component fails, traffic can be automatically rerouted without significant disruption. Fault tolerance mechanisms like failover clusters, data replication, and automatic backups are also essential. Monitoring and alerting systems should be in place to detect and respond to network issues promptly. Furthermore, consider geographic diversity for disaster recovery and utilize techniques like Anycast for resilient service delivery. Network segmentation and security measures are important for preventing unauthorized access and mitigating potential security breaches, contributing indirectly to overall availability.

25

What is a MAC address?

Reference answer

MAC (Media Access Control) address is a unique identifier assigned to each network interface card (NIC). It is a physical address used to identify and communicate with specific devices on a network.

26

How is Password Cracking Performed?

Reference answer

Methods include brute force and dictionary attacks, using tools like John the Ripper and Hashcat.

27

What is the effective length of a single segment of UTP cable and how can this limit be overcome?

Reference answer

A single segment of UTP cable has an effective length of 90 to 100 meters. This limit can be overcome by using repeaters and switches.

28

What factors should be considered when designing a solid disaster recovery plan?

Reference answer

A number of factors need to be cautiously considered when designing a solid disaster recovery plan. Recovery Point Objective (RPO) sets up the maximum allowable data loss, so although Recovery Time Objective (RTO) the maximum allowable downtime. Duplication, which includes hardware, links, and geographically diverse locations, is crucial. It is essential to set up and test thorough data backup and restoration protocols on a regular basis. Minimize manual intervention by implementing automated failover mechanisms. To make sure the plan is effective, it needs to be well documented and tested frequently. Solutions for disaster recovery that are cloud-based offer greater scalability and flexibility.

29

What happens when you type a website address into your browser?

Reference answer

Your browser starts by looking up the website's real address. The name you type is not the actual location. DNS servers translate this name into a numerical IP address. Next, your browser creates a connection to that server. It utilizes the TCP protocol to establish a secure pathway for data transfer. This happens through a three-way handshake process. Your browser then requests the webpage. It sends an HTTP message requesting specific content from the server. This message includes details about what your browser can handle. The server handles this request, and it responds by transmitting the webpage files. The latter consists of HTML, CSS, JavaScript code, and graphics. The files flow back to your device via the internet. Your browser receives all of these components. It reads the code, applies the styling, and executes the scripts, displaying all on your screen as one whole web page. Understanding how browsers, DNS, TCP/IP, and servers communicate is an important part of networking fundamentals and is commonly covered in CCNA training. If you want to learn these concepts practically with real lab experience, you can explore the CCNA Course by PyNet Labs taught by CCIE-certified trainers.

30

Explain different types of networks.

Reference answer

Below are few types of networks: | Type | Description | |---|---| | PAN (Personal Area Network) | Let devices connect and communicate over the range of a person. E.g. connecting Bluetooth devices. | | LAN (Local Area Network) | It is a privately owned network that operates within and nearby a single building like a home, office, or factory | | MAN (Metropolitan Area Network) | It connects and covers the whole city. E.g. TV Cable connection over the city | | WAN (Wide Area Network) | It spans a large geographical area, often a country or continent. The Internet is the largest WAN | | GAN (Global Area Network) | It is also known as the Internet which connects the globe using satellites. The Internet is also called the Network of WANs. |

31

What is a three-tier network architecture?

Reference answer

A three-tier network architecture consists of: A core layer that provides high-speed, reliable connectivity between different parts of the network; A distribution layer that aggregates data from the access layer, enforcing policies and routing decisions; An access layer that connects end devices like computers and printers to the network.

32

How would you define CSMA/ CD?

Reference answer

CSMA/ CD stands for Carrier-sense multiple access Collision Detection. This protocol defines the way two devices interact when a data collision occurs. The protocol has rules of how long the devices in a network must wait when a collision happens. It analyses if the communication channel is busy or not, and controls the transmission accordingly. If it detects a collision, the transmission of the station is stopped. It then sends a jam signal and waits for some time before transmitting again.

33

What is an IPv4 address? What are the different classes of IPv4?

Reference answer

An IP address is a 32-bit dynamic address of a node in the network. An IPv4 address has 4 octets of 8-bit each with each number with a value up to 255. IPv4 classes are differentiated based on the number of hosts it supports on the network. There are five types of IPv4 classes and are based on the first octet of IP addresses which are classified as Class A, B, C, D, or E. | IPv4 Class | IPv4 Start Address | IPv4 End Address | Usage | |---|---|---|---| | A | 0.0.0.0 | 127.255.255.255 | Used for Large Network | | B | 128.0.0.0 | 191.255.255.255 | Used for Medium Size Network | | C | 192.0.0.0 | 223.255.255.255 | Used for Local Area Network | | D | 224.0.0.0 | 239.255.255.255 | Reserved for Multicasting | | E | 240.0.0.0 | 255.255.255.254 | Study and R&D |

34

What are the key considerations for securing data in transit?

Reference answer

Securing data in transit involves encrypting the data, using secure communication protocols like TLS/SSL, and regularly updating cryptographic protocols. Effective key management and balancing security with performance are also crucial considerations.

35

What are the challenges of securing Industrial Control Systems (ICS)?

Reference answer

Securing ICS can be challenging due to legacy systems with limited security, disruption risks from maintenance windows, and the need to balance security with operational efficiency. Effective security requires robust authentication, regular assessments, and vulnerability management.

36

What is a wireless repeater?

Reference answer

A wireless repeater extends the range of a wireless network by receiving the signal from a WAP and retransmitting it at a higher power. It amplifies the signal to cover areas where the original WAP's signal is weak.

37

What are the common types of wireless encryption and why is encryption important?

Reference answer

The common types of wireless encryption are WEP, WPA, and WPA2. Encryption is essential for securing data transmitted over wireless networks, preventing unauthorized access and protecting user privacy.

38

What is SNMP?

Reference answer

SNMP stands for Simple Network Management Protocol. SNMP is a network protocol that allows data collection, organization, and transmission among network devices. SNMP is a prevalent tool in network management, utilized to configure various network devices such as hubs, servers, routers, printers, and switches. Critical components of SNMP are: - Management Information Base (MIB) - SNMP Manager - SNMP Agent - Managed device

39

What is Network Address Translation (NAT) and what is its primary role?

Reference answer

Network Address Translation (NAT) is a technique used to map private IP addresses to a single public IP address, or a small pool of public IP addresses. Its primary role is to conserve public IP addresses, which are a limited resource. Without NAT, every device on a private network would require a unique public IP address to communicate with the internet. With NAT, multiple devices within a private network can share a single public IP address, as the NAT router translates the private IP addresses of internal devices to the public IP address when traffic leaves the network, and vice versa when traffic returns. This allows organizations to use private IP address ranges internally, significantly reducing the demand for globally unique public IP addresses. Furthermore, NAT provides a basic level of security by hiding the internal network structure from the outside world. External devices only see the public IP address of the NAT router, making it more difficult for attackers to directly target individual devices on the internal network. However, NAT is not a replacement for a firewall; it is a complementary security measure.

40

Define the 7 different layers of the OSI Reference Model

Reference answer

Here the 7 layers of the OSI reference model: | Layer | Unit Exchanged | Description | |---|---|---| | Physical | Bit | (No description provided) | | Data Link | Frame | (No description provided) | | Network | Packet | (No description provided) | | Transport | TPDU - Transaction Protocol Data Unit | (No description provided) | | Session | SPDU - Session Protocol Data Unit | (No description provided) | | Presentation | PPDU - Presentation Protocol Data Unit | (No description provided) | | Application | APDU - Application Protocol Data Unit | (No description provided) |

41

Describe networking.

Reference answer

Networking alludes to the interconnection among PCs and peripherals for information correspondence. Networking should be possible utilizing wired cabling or through a remote connection.

42

What is SQL Injection?

Reference answer

SQL injection exploits input data to manipulate SQL queries, enabling attackers to control the database. Prevention includes input filtering, parameterized queries, and restricted database permissions.

43

What is a Network Proxy?

Reference answer

A Network Proxy intermediates between client devices and the internet, handling requests and responses. It enhances privacy and security by providing anonymity, filtering content, and hiding users' IP addresses while protecting against malicious threats.

44

How can you configure Wi-Fi network and what are Wi-Fi Protocols?

Reference answer

1) Basically there are many standards of Wi-Fi in the industry but some popular of them are 802.11a, 802.11b, 802.11g/n. With the support of these Wi-Fi protocols we can communicate/interact among the devices at the speed of 5Ghz to 2.4Ghz dual band communication. 2) If we have Wi-Fi nic card so firstly we have to install their drivers and after installation if we have Wi-Fi access point then we can see the signal strength in the right corner below just open that and find the access point to connect, if access point is configured with the security, type the key to connect and enjoy the service. 3) Wi-Fi is technically referred to as the 802.11 protocol. Over time, Wi-Fi has improved, giving rise to different variations of the protocol. 802.11a – This version operates at 54Mbps. It is considered as the favorite wireless LAN protocol for IP telephony.

45

Describe the most challenging network issue you've encountered in your work or projects and how you solved it.

Reference answer

This question evaluates practical experience and problem-solving skills. Candidates should describe the issue's context, analysis, solution, and outcomes in detail.

46

What are some of the advantages of a mesh Wi-Fi system?

Reference answer

Advantages include: - Wider coverage and better signal strength. - Improved performance and reliability. - Simplified setup and management. - Self-healing capabilities.

47

What are some common network security threats?

Reference answer

Some common network security threats include malware (viruses, worms, trojans), phishing attacks (deceptive emails or websites), ransomware (encrypting data and demanding payment), denial-of-service (DoS) and distributed denial-of-service (DDoS) attacks (overwhelming a system with traffic), man-in-the-middle (MitM) attacks (intercepting communication), and SQL injection (exploiting vulnerabilities in databases). It's also important to be aware of insider threats (malicious or negligent employees), weak passwords, unpatched software vulnerabilities, and social engineering (manipulating individuals to gain access or information). Staying informed about the latest threat landscape and implementing appropriate security measures are crucial for protecting a network.

48

What is channel overlap, and why is it a concern in wireless networking?

Reference answer

Channel overlap occurs when two or more channels on the same frequency band overlap, causing interference and reduced performance. It is essential to select non-overlapping channels to minimize interference and ensure optimal signal quality.

49

Explain the concept of a VLAN

Reference answer

Virtual local area network, also known as VLAN divides a large network into smaller independent sections. A device in one VLAN communicates with another device in the same VLAN, as though it is in its own bubble, despite existing in the same physical system. This makes things neat and safe. When a problem, such as a virus, occurs in one VLAN, it remains there and does not propagate. It also decreases network congestion; data travels at a higher rate. VLANs simplify management of networks without additional hardware or cables requirements. They are an intelligent means of managing devices, improving security and keeping things going effortlessly.

50

Describe Network Topology

Reference answer

Network Topology alludes to the design of a PC network. It shows how network gadget and links are genuinely spread out, just as how they associate.

51

What is the difference between a Wi-Fi router and a Wi-Fi extender?

Reference answer

- Wi-Fi router: Provides internet connectivity and acts as a central point for wireless connections. - Wi-Fi extender: Extends the range of an existing Wi-Fi network by amplifying the signal.

52

How would you be able to deal with a network utilizing a switch?

Reference answer

Switches have an implicit comfort that allows you to arrange various settings, similar to security and information logging. You can appoint limitations to PCs, for example, what assets it is permitted admittance or what specific time they can peruse the Internet. You can even put limitations on what sites are not visible across the whole network.

53

What is the OSI model and what are its seven layers?

Reference answer

The OSI model, or Open Systems Interconnection model, is a conceptual framework used to understand how different network protocols interact and work together to provide network services. The model is divided into seven layers starting from physical to application. At the bottom, we have the Physical layer (Layer 1), which encompasses the physical equipment involved in data transmission, such as cabling and connections. Above this is the Data Link layer (Layer 2), which handles error-free transmission of frames from one node to another. Next, we have the Network layer (Layer 3), responsible for data routing through different networks. The Transport layer (Layer 4) controls the reliability of a given link through flow control, segmentation/desegmentation, and error control. Session layer (Layer 5) manages sessions between applications. Presentation layer (Layer 6) handles syntax and semantics of data to be sent over a network. And finally, the Application layer (Layer 7) facilitates interactions between networked applications and the user. So, basically, data starts at the top (application layer) and works its way down through the layers adding extra bits of information, like source and destination addresses, as it goes, before eventually being sent across the network at the physical layer.

54

What is a subnet and why are subnets used?

Reference answer

A subnet, or subnetwork, is a logical subdivision of an IP network. It's created by dividing a single network into multiple smaller, interconnected networks. This division is achieved by manipulating the network's address space using subnet masks. Subnets are used for several reasons, primarily to improve network organization, security, and performance. They help in: - Reducing network congestion by containing broadcast traffic within the subnet - Enhancing security by isolating network segments - Simplifying network management and troubleshooting - Efficiently utilizing IP address space

55

What career goals do you have in the wireless network engineering space?

Reference answer

This question helps understand the candidate's long-term ambitions and alignment with the role.

56

What are the authentication mechanisms supported by Cisco Access Points?

Reference answer

Mechanisms Include: WEP, WPA, WPA2, EAP, MAC authentication.

57

What is a tracert command?

Reference answer

The tracert command is used for displaying information about the path taken by a data packet to reach the destination network from the router. The total number of hops taken by the packet during the transmission is also displayed.

58

Which technique is used in byte-oriented protocols?

Reference answer

Byte stuffing is used in byte-oriented protocols. A special byte is added to the data section of the frame when there is a character with the same pattern as the flag.

59

What is a router and what is its main job?

Reference answer

A router is a networking device that forwards data packets between computer networks. It acts as a traffic controller for network data. The main job of a router is to determine the best path for data packets to travel from their source to their destination. It does this by examining the destination IP address of each packet and using routing tables to decide where to send the packet next. This process is known as routing.

60

Describe the generic EAP process

Reference answer

Talk about the different entities involved like the authenticator, endpoint, authentication server etc.

61

TCP handshakes, TCP Windowing

Reference answer

You can google it :)

62

What is a near - far issues in terms of wifi

Reference answer

Please refer to CWNA Chapter on WLAN troubleshooting

63

What is SNR? How do you fix SNR issues?

Reference answer

SNR stands for Signal-to-Noise Ratio, a measure of signal quality. Fixing SNR issues involves reducing noise sources, improving antenna placement, or adjusting power levels.

64

How do you prioritize network tasks in a high-pressure environment?

Reference answer

Assessment: Analyze the candidate's ability to manage workload effectively, prioritize tasks based on urgency, and remain calm under pressure. Red flags: Difficulty articulating strategies for managing workload or a lack of examples demonstrating successful prioritization may suggest poor time management skills.

65

What is IBSS and BSS?

Reference answer

IBSS (Independent Basic Service Set): Direct device-to-device communication without a central device. BSS (Basic Service Set): Wireless LAN established using an Access Point.

66

What is Biometric Authentication?

Reference answer

Biometric Authentication uses unique biological traits for user identification, providing strong security through difficult-to-replicate credentials. It reduces the risk of unauthorized access from stolen passwords and adds an extra security layer when biometric data is encrypted.

67

What is a Buffer Overflow Attack and How is it Prevented?

Reference answer

A buffer overflow occurs when a program writes data beyond a buffer's capacity, allowing the execution of malicious code. Prevention includes boundary checks and using secure programming languages.

68

What is the difference between a forward proxy and a reverse proxy?

Reference answer

A forward proxy and a reverse proxy both work as a middleman in a network, but their differences lie in who they protect and where they are placed in a network. | Forward Proxy | Reverse Proxy | | It works for users/clients. | It mainly works for servers. | | It sits in front of users. | It sits in front of the servers. | | It is used to hide the client's identity. | It is used to hide the server's identity. | | Used inside organizations | Used in data centers and websites | | It primarily controls the user's internet access. | It primarily controls incoming user requests. |

69

How Do You Troubleshoot Network Issues?

Reference answer

- Check physical connections - Use ping andtraceroute - Analyze configurations ( show run ) - Review logs ( show log , Syslog) - Verify interface status ( show ip interface brief )

70

What happens when you type a website address (like www.example.com) into your browser and press Enter?

Reference answer

When you type a website address (like www.example.com ) into your browser and press Enter, several things happen. First, the browser checks its cache and the operating system's DNS cache for the IP address associated with the domain name. If not found, it queries a DNS server (typically provided by your ISP) to resolve the domain name to an IP address. The browser then establishes a connection with the server at that IP address, usually via TCP. Once connected, the browser sends an HTTP request to the server, requesting the content of the specified page (e.g., /index.html ). The server processes the request and sends back an HTTP response, which includes the requested content (HTML, CSS, JavaScript, images, etc.) and other information, such as the HTTP status code. The browser then renders the content, displaying the webpage to you. This rendering process involves parsing the HTML, applying the CSS styles, and executing any JavaScript code.

71

What is LTE (Long Term Evolution)?

Reference answer

LTE is a high-speed wireless communication standard for mobile networks, considered a 4G technology. It provides faster data rates and improved performance compared to previous generations.

72

What is the difference between IPS and a firewall?

Reference answer

The Intrusion Prevention System is also known as Intrusion Detection and Prevention System. It is a network security application that monitors network or system activities for malicious activity. The major functions of intrusion prevention systems are to identify malicious activity, collect information about this activity, report it, and attempt to block or stop it. Intrusion prevention systems are contemplated as augmentation of Intrusion Detection Systems (IDS) because both IPS and IDS operate network traffic and system activities for malicious activity. IPS typically records information related to observed events, notifies security administrators of important observed events, and produces reports. Many IPS can also respond to a detected threat by attempting to prevent it from succeeding. They use various response techniques, which involve the IPS stopping the attack itself, changing the security environment, or changing the attack's content. A firewall is a network security device, either hardware or software-based, which monitors all incoming and outgoing traffic, and based on a defined set of security rules it accepts, rejects, or drops that specific traffic.

73

How does BGP select the best path for routing?

Reference answer

BGP uses various attributes, such as AS path, next hop, local preference, MED (Multi-Exit Discriminator), Weight (prefer the path with the highest weight. This is a value that is local to the router, and it's Cisco proprietary. The default value is 0 for all routes not originated by the local router), to select the best path. It evaluates these attributes to determine the most efficient route for data.

74

What is the difference between a static and dynamic IP address?

Reference answer

A static IP address, as the name implies, is an IP address that doesn't change. It remains the same each time a device connects to the network. They're beneficial for services that require a persistent known IP, like web servers, mail servers, or network infrastructure devices, so that other devices always know how to reach them. On the other hand, a dynamic IP address is one that can change every time a device connects to the network. Dynamic IP addresses are assigned from a pool of available addresses by the Dynamic Host Configuration Protocol (DHCP) server in the network. Once a device is done using an IP and disconnects from the network, that IP is put back into the pool and can be reassigned to another device. Dynamic IPs are more common for residential users and small businesses as they are cost-effective and don't require management. However, they can be less ideal for hosting certain services because if the IP changes, external systems trying to reach the service will no longer find it at the old IP. So the choice between a static and dynamic IP address primarily depends on the specific requirements and resources of your network.

75

Detail the installation steps for 5G network components.

Reference answer

Installing 5G network components requires precision and expertise. The installation process includes mounting gNBs, connecting backhaul links, configuring antennas, and integrating core network elements. Each step is crucial to ensure that the network components operate seamlessly, delivering the promised speed, reliability, and low latency.

76

How do you ensure compliance with network security policies and regulations?

Reference answer

Ensuring compliance with network security policies and regulations involves a multi-faceted approach. Key aspects include: - Implementing and enforcing security policies and procedures. - Conducting regular security audits and vulnerability assessments. - Using network monitoring and logging to detect and respond to security incidents. - Ensuring proper access controls and authentication mechanisms. - Keeping systems and software up-to-date with security patches. - Providing security awareness training to employees. - Documenting all security measures and compliance activities. - Working with legal and compliance teams to understand and meet regulatory requirements. Effective compliance requires continuous monitoring, evaluation, and adaptation to the evolving threat landscape and regulatory requirements. Automation wherever possible improves efficiency and reduces error.

77

What are CNA interview questions for beginners?

Reference answer

CNA interview questions for beginners, with a simple answer framework, sample responses, and the questions hiring managers actually care about when you have.

78

What is VLAN?

Reference answer

VLAN (Virtual Local Area Network) logically segments a LAN into subnetworks without physical separation, preventing broadcast storms and enhancing security.

79

What is a Domain Controller in an Internal Network?

Reference answer

A domain controller manages the internal network, including user authentication, permission management, and policy distribution.

80

How many (max) mac addresses are present in a 802.11 header

Reference answer

Four - Sender Address (SA), Transmitter address (TA), Destination address (DA) and Receiver address (RA)

81

What is the significance of channel planning in a wireless network?

Reference answer

Channel planning involves selecting and configuring wireless channels to minimize interference and optimize network performance. Proper planning ensures that adjacent access points use non-overlapping channels to avoid co-channel interference.

82

What is Netstat?

Reference answer

Netstat stands for network statistics. It is a network utility of the command line. This command is used for displaying information about the TCP/IP settings, incoming and outgoing connections, network protocol statistics and routing tables. The command is used on Windows and Unix operating systems. Netstat is useful for determining the network traffic and problems in the network. On a Windows system, the command netstat can be entered in the command line. You will see a list of all active network connections.

83

What are some common wireless networking standards?

Reference answer

Common standards include: - IEEE 802.11a/b/g/n/ac/ax (Wi-Fi) - Bluetooth - Zigbee - Z-Wave

84

What is the difference between a public and private IP address?

Reference answer

Public and private IP addresses serve different purposes in network communication. A public IP address is assigned to your network by your Internet Service Provider (ISP) and is used for communicating directly with the internet. It's globally unique and allows devices on the internet to find and communicate with your network. In contrast, a private IP address is used within a private network, such as your home or office. These addresses are not routable on the internet and are assigned to devices within the network by a router. Private IP address ranges include: 10.0.0.0 - 10.255.255.255 172.16.0.0 - 172.31.255.255 192.168.0.0 - 192.168.255.255 Network Address Translation (NAT) is commonly used to translate private IP addresses to a single public IP address for internet communication.

85

What is PoE (Power over Ethernet)?

Reference answer

PoE delivers electrical power and data over a single Ethernet cable to devices like IP phones, cameras, and access points.

86

Explain the concept of RSSI (Received Signal Strength Indicator).

Reference answer

RSSI measures the strength of the received wireless signal. It is used to determine the quality of the connection between a wireless client and an access point. Higher RSSI values indicate stronger signals and better connectivity.

87

What is DNS and how does it work?

Reference answer

The Domain Name System, or DNS, is essentially a phone book for the internet. It's a protocol within the set of internet standards that transforms human-friendly domain names into computer-friendly IP addresses, which are numerical. Imagine you want to visit a website, say "www.example.com". You type that URL into your browser, and your computer then sends a query over the internet to your DNS server to ask for the corresponding IP address. The DNS server looks this up, often with the help of other DNS servers, and sends back the IP address (e.g., 192.0.2.0). Your computer then communicates with that IP address to fetch the webpage you wanted. This process is vital because while domain names are easier for people to remember, computers or servers on the internet locate each other using IP addresses. By converting domain names into IP addresses, DNS makes it possible for people to connect to websites using language that is easy to understand, instead of having to remember a string of numbers. Therefore, DNS plays a vital role in ensuring the smooth operation of internet services.

88

Describe the concept of Wi-Fi security and list some common security protocols.

Reference answer

Wi-Fi security protects wireless networks from unauthorized access and data breaches. Common security protocols include: - - WEP (Wired Equivalent Privacy): An older and less secure protocol. - WPA (Wi-Fi Protected Access): Provides improved security over WEP. - WPA2: Uses AES encryption for stronger security. - WPA3: Offers enhanced security features and protection against brute-force attacks.

89

What is PCI DSS, and why is it important for network engineers?

Reference answer

PCI DSS (Payment Card Industry Data Security Standard) is a framework that ensures the security of systems that handle cardholder data. Network engineers must design and maintain systems that comply with PCI DSS to protect sensitive payment information.

90

What is a ping command? What is TTL?

Reference answer

Here's what you need to remember: A ping command is given because it is the simplest way to check if a system is reachable over a network But how does it work? So, when you run a ping, your machine sends an ICMP Echo Request to the destination. If the destination is reachable, it replies with an ICMP Echo Reply. And so, ping is responsible for 2 things, and those are if the system is reachable or just how long it would take, i.e, the round-trip time. Now, along with this, every packet also carries something called TTL, i.e, Time To Live. TTL is just a counter inside the IP packet. Each time the packet passes through a router, the TTL is reduced by 1. When it reaches 0, the packet is discarded, and the router sends back an ICMP ‘Time Exceeded' message. You might be wondering what is the need of these So, essentially, because without TTL, a packet stuck in a routing loop could keep circulating forever. And that is why TTL helps packets eventually expire. One thing you probably would notice in ping output is the TTL value. Different systems use different default TTLs, for example, Linux/macOS - around 64 and Windows - around 128. So sometimes, you can roughly guess the OS based on the TTL in the reply. When we look at traceroute and how it connects: traceroute cleverly uses TTL. It sends packets with TTL = 1, then 2, then 3… Each router drops the packet when TTL becomes 0 and replies back. This is how traceroute maps the path from source to destination. And voila, this is everything you can cover for a ping-related question, but yes, there can be a follow-up question in the interview, like: Q. If ping works but HTTP doesn't, what does that mean? Your ans: It means basic network connectivity is fine. The issue is likely at a higher layer, for example, a blocked port, a service not running, or an application-level problem.

91

What is a wireless mesh network?

Reference answer

A wireless mesh network uses multiple access points (nodes) that connect to each other wirelessly, forming a self-healing network. If one node fails, data can be routed through other nodes, ensuring continuous connectivity.

92

How do you ensure network security in a dynamic environment?

Reference answer

Assessment: Assess the applicants' understanding of network security principles and their ability to implement measures to safeguard network integrity and data confidentiality. Red flags: Vague responses or overlooking key security considerations may suggest a lack of attention to detail or inadequate security knowledge.

93

How is Network Deception Technology Implemented?

Reference answer

Network deception technology misleads attackers by creating fake environments or information, such as honeypots or false network topologies.

94

What is DNS and Its Role?

Reference answer

The Domain Name System (DNS) converts human-readable domain names to IP addresses. Components: - Resolver: Client sending the query. - Root, TLD, and Authoritative servers: Hierarchical structure for resolution. Example: Resolving “www.cisco.com” to an IP like 198.133.219.25.

95

Can you explain subnetting and its importance in IP addressing?

Reference answer

Subnetting is a method used in IP networking to divide a larger network into smaller, more manageable sub-networks or subnets. Each subnet operates as a distinct network with its own range of IP addresses. This organization enhances network efficiency, security, and management. Importance of Subnetting: - Efficient IP Address Management: By dividing a large network into smaller subnets, IP addresses can be used more efficiently. This helps in avoiding the wastage of IP addresses and ensures that each subnet gets an appropriate number of addresses based on its needs. - Improved Network Performance: Subnetting helps in reducing broadcast traffic by limiting the broadcast domain to a smaller subnet. This results in improved network performance and reduced network congestion. - Enhanced Security: Subnets can be used to isolate different segments of a network, improving security by controlling the flow of traffic between them. For instance, sensitive systems can be placed in separate subnets with strict access controls. - Simplified Network Management: Network management becomes easier when dealing with smaller subnets. It allows for better organization of network resources and more straightforward network troubleshooting and monitoring. The suffix /24 means that 2^(32–24)=256 addresses are available to use: - 10.0.1.0 represents the subnet itself and cannot be assigned to individual device. - First 254 addresses are available host addresses: 10.0.1.1–10.0.1.254. - 10.0.1.255 is the 255th (last, counting from 0) address which is allocated for the broadcast address — The broadcast address is a special IP address used to send data packets to all devices on a network or subnet simultaneously. It allows a single message to be delivered to every device within the same network segment without needing to send individual packets to each device. Network Address + Usable Addresses + Broadcast Address: 1 (Network) + 254 (Usable) + 1 (Broadcast) = 256

96

Explain How NAT Works.

Reference answer

NAT (Network Address Translation) enables devices on a private network to communicate with external networks using a shared public IP. It replaces private IP addresses with public ones and records mappings to ensure proper response routing.

97

Can you discuss your experience with cloud networking technologies and platforms?

Reference answer

Assessment: Determine the interviewees' familiarity with cloud networking technologies like AWS, Azure, or Google Cloud. Check their ability to integrate cloud solutions into traditional network environments. Red flags: Limited experience with cloud networking or an inability to discuss relevant projects may indicate a lack of adaptability or exposure to modern networking trends.

98

How would you troubleshoot low throughput issue on the wifi network

Reference answer

There is no real ‘correct' answer for such open ended questions. The interviewer is trying to access your analytical thinking and troubleshooting skills. If the interview is for a customer rep or test engineer, this question would be very important. Throughput issues can steam from variety of root causes. It is important to ask a few questions and understand what is the problem symptom before you get started. You should look at the data rate at which the client is connecting (802.11n, ac etc), what MCS rate and the clients capability, SNR, RSSI of the client to start off with. A handy tool is WLC / AP debugs logs in conjunction with Over-the-air 802.11 sniffer captures. You can follow the traffic pattern (you won't be able to decode the actual qos data on most occasions) to try and get a sense of any RF issues (if you see too many Retries or rate downshift). On odd occasion if there is a bug you may land up with incorrect sequencing of the data frames, qos mis configs and potential A-MPDU issues. Next step once you are past the Layer 1 and 2 of the OSI model is to start exploring the layer 3 traffic (decapsulated, preferably at the VLAN level or default gateway). Check for TCP windowing issues or retransmit etc. The problem could be between specific hosts/ servers etc.

99

What is data encapsulation?

Reference answer

Data encapsulation is the process of breaking data into smaller, manageable pieces before it is transmitted across the network. In this process, source and destination addresses are appended to the headers, along with error checks.

100

What is the difference between LTE and 5G in terms of latency and data rate?

Reference answer

LTE offers latency around 10-20 ms and peak data rates up to 1 Gbps, while 5G targets latency as low as 1 ms and peak data rates up to 20 Gbps, enabling ultra-reliable low-latency communication (URLLC) and enhanced mobile broadband (eMBB).

101

What is Piggybacking in the context of Wi-Fi?

Reference answer

Piggybacking: Unauthorized use of someone else's wireless connection without their permission.

102

What is a wireless network key?

Reference answer

A wireless network key, also known as a passphrase, is a password used to secure a wireless network. It is used to authenticate devices and prevent unauthorized access.

103

What are VLANs?

Reference answer

VLANs divide a physical network into multiple logical networks, improving performance and security by isolating broadcast domains. This segmentation reduces the risk of unauthorized access and limits the impact of potential security incidents.

104

What are the different types of network delays?

Reference answer

Mainly the different types of network delays are: propagation delay, transmission delay, processing delay, and queueing delay. I'll explain everything in-depth! You know when data travels from one system to another, almost every time you face a certain delay. This process is basically called a total delay or latency and it's made up from multiple smaller delays. So, here is how it goes: Propagation delay is the time it takes for the signal to physically travel from sender to receiver. Now, a propagation delay completely depends on distance and the medium such as fiber, copper, etc., so even at high speeds, long distances do add delay. And then, comes your transmission delay. This is the time required to push all bits of a packet onto the wire. So if the packet is large or the bandwidth is low, this delay eventually increases. Now, once the packet reaches a router, it doesn't immediately move ahead. There's a small processing delay, where the router checks the packet header and decides where to send it next. Even after everything is covered, there is still some time where the packet has to wait. That waiting time is called queuing delay. Remember that this is the most unpredictable one; it depends on network congestion. If many packets arrive at the same time, some of them sit in a buffer before being forwarded. Here's what you should note: Bandwidth and latency are often confused with one another. So this is how you can differentiate it, A bandwidth is like the number of lanes on a highway, while latency is the speed limit. You can have a wide road, i.e, high bandwidth, but if the speed is low, i.e, high delay, things still move slowly.

105

What are the key improvements of IPv6 over IPv4?

Reference answer

IPv6 offers a larger address space with 128-bit addresses, solving IPv4 exhaustion. It has a streamlined header format, improving processing efficiency, and supports auto-configuration and plug-and-play features. IPv6 also enhances security and mobility.

106

How do you balance security and performance in network design?

Reference answer

Security and performance often conflict in network design. Strengthening security measures (e.g., firewalls, intrusion detection systems) can increase latency and reduce performance, while focusing on high performance may compromise security. The key is to strike a balance by prioritizing based on actual needs and making reasonable trade-offs.

107

Name two devices that can interfere with the operation of a wireless network because they operate on similar frequencies.

Reference answer

Two devices that can interfere are microwave ovens and cordless phones, as they often operate on the 2.4 GHz frequency.

108

What is a switch and how does it work?

Reference answer

Switches can connect two or more network segments. These are intelligent network devices that store information in their routing tables, like paths, hops, and bottlenecks. With this information, they can determine the best path for data to move. Switches work at the OSI Network Layer.

109

Describe a time you ran into a problem when you were in the field you didn't know how to solve right away, and how did you address it?

Reference answer

This question assesses problem-solving skills and the ability to handle unexpected challenges in real-world wireless network scenarios.

110

What is Network Address Translation (NAT)?

Reference answer

NAT converts private IP addresses within a local network to a single public IP address, creating a barrier between internal and external networks. This helps protect internal network details, making it harder for attackers to directly target specific devices.

111

What is NAT?

Reference answer

NAT stands for Network Address Translation. The process of NAT involves converting a specific range of private IP addresses to a single public IP address linked to a gateway device. The network address translation process allows a single device to act as an intermediary or agent between a private, localized network and a public network, such as the Internet. The main focus of NAT is to conserve public IP addresses.

112

What is the difference between Hub, Switch, and Router?

Reference answer

Here is a table explaining the difference between Hub, Switch, and Router – | Device | Layer (OSI Model) | Function | Example | | HUB | It works on Layer 1 i.e., Physical Layer | Connects multiple devices on a single network and broadcasts data to all ports. | A hub can be used to connect four computers in a small office network. | | Switch | It works on Layer 2 i.e., Data Link Layer | Connects multiple devices on one or more networks and forwards data to the destination port based on MAC address. | A switch can be used to create VLANs and reduce broadcast traffic. | | Router | It works on Layer 3 i.e., Network Layer | Connects two or more networks and routes data based on IP address. | A router can be used to connect a home network to the internet and provide firewall protection. |

113

What is a wireless card?

Reference answer

A wireless card is an internal component within a computer that provides wireless network connectivity. It acts as a network interface card (NIC) for wireless communication.

114

Explain the TCP three-way handshake.

Reference answer

The three-way handshake happens as: - SYN: The client sends a synchronization request to start a connection. - SYN-ACK: The Server acknowledges and sends a synchronization request. - ACK: The client acknowledges the server's request and completes the handshake.

115

What is the customer/worker?

Reference answer

Customer or worker is a kind of network wherein at least one PC's go about as workers. Workers give an incorporated store of assets like printers and records. Customers allude to a workstation that gets to the worker.

116

What is NAT (Network Address Translation)? Why is it used?

Reference answer

NAT is a networking technique. It is used by routers, so that private networks on multiple devices can share a singular IP address to access the internet. But why is it needed? Devices inside a network use private IPs, which are not directly accessible on the internet. So when a request is sent out, the router replaces the private IP with its own public IP. When the response comes back, the router uses a mapping to forward it to the correct device. This mechanism especially became necessary because IPv4 addresses were limited. And that is why, instead of assigning a unique public IP to every device, NAT made it so, that multiple devices could share a single public IP. You should also note the different types of NAT: Static NAT creates a fixed one-to-one mapping between a private and public IP which is usuallu used for servers. Whereas, Dynamic NAT uses a pool of public IPs and assigns them as needed. But even so, the most commonly used form is PAT, also known as NAT overload. In PAT, multiple devices share the same public IP, and connections are distinguished using port numbers. The router maps internal IP and port combinations to a unique external port which helps with the multiple simultaneous connections. One thing you should keep in mind about NAT is that it breaks end-to-end connectivity. External systems cannot directly initiate communication with devices inside a private network unless additional configurations like port forwarding are used. And this limitation is one of the many reasons why IPv6 was designed, where each device can have a globally unique address and NAT is not required.

117

What is the difference between IPv4 and IPv6?

Reference answer

IPv4 and IPv6 are different versions of the Internet Protocol, used for addressing and identifying devices on a network. IPv4 uses a 32-bit address (e.g., 192.168.1.1 ), allowing for approximately 4.3 billion unique addresses. IPv6 uses a 128-bit address (e.g., 2001:0db8:85a3:0000:0000:8a2e:0370:7334 ), providing a vastly larger address space (2128 addresses), essentially solving the IPv4 address exhaustion problem. IPv6 also incorporates improvements like stateless address autoconfiguration and enhanced security features compared to IPv4. The headers differ as well, IPv6 has a simplified header making it more efficient.

118

How do you secure IoT devices?

Reference answer

IoT devices often have limited built-in security features and may be vulnerable if not configured correctly. Securing these devices requires robust authentication, encryption, and monitoring to prevent unauthorized access and exploitation.

119

What do you understand by Sneakernet?

Reference answer

It is the earliest form of networking where data is physically transferred through removable media.

120

What is CIDR?

Reference answer

CIDR is Classless Inter-Domain Routing. It is a way of assigning IP addresses in a more efficient manner compared to older ones. Before CIDR, IP addresses were divided into fixed classes. This wasted many addresses because organizations often got more than they needed. CIDR solved this problem by allowing flexible network sizes. CIDR uses a slash notation to show network size, i.e., 192.168.1.0/24. The number after the slash will indicate the number of bits utilized by the network portion. The remaining bits are for individual device addresses. This system allows networks to be any size needed. Small networks can get just a few addresses. Large networks can get thousands. This reduces the amount of information that routers must store and process. CIDR also helps routers work more efficiently. It allows them to group multiple networks together in a single routing table. This reduces the amount of information routers need to store and process. Modern internet infrastructure cannot survive without the system. It helps control the scarcity of IPv4 addresses and is also expected to aid in the development of internet-enabled devices.

121

Which layer of the OSI model is responsible for physical addressing, such as MAC addresses?

Reference answer

Data Link Layer (Layer 2)

122

What are the differences between a hub, a switch, and a router?

Reference answer

A hub is a simple device that broadcasts all incoming traffic to every connected device, leading to collisions and poor performance. A switch learns MAC addresses and forwards traffic only to the intended recipient, improving efficiency. A router connects different networks and routes traffic based on IP addresses, enabling communication between networks and providing network segmentation.

123

What is a wireless network profile?

Reference answer

A wireless network profile stores the settings for a specific wireless network, including the SSID, security type, and password. It allows devices to easily connect to known networks.

124

What is LACP and what are its benefits?

Reference answer

The Link Aggregation Control Protocol (LACP) combines multiple physical links into a single logical link, increasing bandwidth, providing redundancy, and balancing the traffic load across all available connections. This improves overall network performance, providing higher data transfer rates and robust fault tolerance, which is key for high-demand environments like data centers and enterprise networks.

125

How is sending a letter similar to how computers send data over a network?

Reference answer

Sending a letter is similar to how computers send data over a network in several ways. Both involve breaking down a larger message into smaller, manageable units (packets in networking, pages/sections in a letter). The letter needs an address (IP address) to ensure it reaches the correct recipient, just like data packets do. The sender (computer sending data) relies on a system (postal service/network protocols) to deliver the message reliably. Finally, just like a letter might have a return address, data packets often contain information about the sender for acknowledgements or replies. Consider a scenario where some pages of a letter get lost in transit. Networking protocols like TCP have mechanisms to detect lost packets and request retransmission, ensuring reliable delivery, similar to resending missing pages of the letter.

126

What is the spine network?

Reference answer

A spine network is a concentrated foundation that is intended to circulate various courses and information to different networks. It additionally handles the administration of bandwidth and different channels.

127

What is TCP/IP Model and how it differs from OSI Model?

Reference answer

The TCP/IP (Transmission Control Protocol/Internet Protocol) is a set of communication protocols that are used to connect network devices on the Internet. The TCP/IP model has 4 layers, unlike the 7 layers of the OSI model. - Network Interface Layer - Internet Layer - Transport Layer - Application Layer The key difference is that TCP/IP is the actual protocol suite used in the real world, while the OSI model serves as a conceptual guideline.

128

What are microservices interview questions with answer frameworks?

Reference answer

Microservices interview questions with answer frameworks, trade-off reasoning, and interview-ready phrasing. Learn key differences and practical steps.

129

What is NOS in Computer Networking?

Reference answer

The Network Operating System (NOS) is specialised software that manages and administers network resources, devices, and services in Computer Networks. NOS is distinguished by its focus on promoting network-centric functionalities and acts as the foundation of network infrastructure management. NOS platforms empower Network Administrators to streamline network operations and optimise resource utilisation.

130

What is a MAC address?

Reference answer

A MAC (Media Access Control) address is a unique hardware address that identifies each network interface card (NIC) on a network. It's like a physical address permanently assigned to the NIC by the manufacturer. It is used for communication within a network segment. Think of it like a postal address for a specific device on a local network. The first three octets usually identify the manufacturer (OUI), while the last three are a unique serial number. MAC addresses are 48 bits long, typically represented in hexadecimal format (e.g., 00:1A:2B:3C:4D:5E ).

131

What is the purpose of a wireless site survey?

Reference answer

A wireless site survey is conducted to assess the RF environment and determine the best placement of access points to provide optimal coverage and performance for a wireless network.

132

What are the benefits of SD-WAN?

Reference answer

Here are some benefits of SD-WAN: - It simplifies WAN Management. - It reduces WAN costs. - Provides more security. - Increased Bandwidth and efficiency. - It provides easier network management. Learn the benefits of SD-WAN in detail.

133

What advanced techniques do you use for network monitoring and threat detection?

Reference answer

Advanced techniques for network monitoring and threat detection include: ● Behavioral Analysis: Use machine learning and behavioral analysis to detect anomalies and deviations from normal network behavior. ● Threat Intelligence: Integrate threat intelligence feeds to stay updated on emerging threats and attack patterns. ● Network Traffic Analysis: Employ tools to analyze network traffic patterns for signs of suspicious activity or potential attacks. ● SIEM (Security Information and Event Management): Implement SIEM systems to aggregate, analyze, and correlate security events and logs for comprehensive threat detection. ● Zero Trust Architecture: Implement a zero-trust model where no entity is trusted by default, and access is continuously verified.

134

How to crack Wi-Fi network, if you are using WEP (Wired Equivalent Privacy) Password with backtrack?

Reference answer

1) The first line of defense of your Wi-Fi network is encryption, which encodes the data transmitted between your PC and your wireless router. 2) WEP abbreviates (Wireless Encryption Protocol). It is a less-secure protocol than WPA (Wireless Protected Access). Since WEP is relatively easy to crack, so you have to use the same form on all devices on your network. If you have an older router that supports WEP only you'll be best safest if you use 128-bit bit WEP keys but also check the manufacturer's Web site for a firmware update that will add WPA support. 3) Two of the most popular programs used for actually cracking the WEP key are Airsnort and Aircrack. Airsnort can be used with the .dump files that Kismet provides; and Aircrack can be use with .cap files that Airodump provides.

135

Enumerate and briefly explain the various handover types in 5G NR.

Reference answer

Handovers are crucial for seamless mobility in 5G networks. The three main handover types are intra-NR, inter-NR, and Xn-based handovers. Here's a detailed explanation: a) Intra-NR handovers: Occur within the 5G network, maintaining the connection as the user moves within the coverage area. b) Inter-NR handovers: Involve transitioning between 5G networks, ensuring uninterrupted service. c) Xn-based handovers: Utilise the Xn interface for handovers between cells served by different gNBs, enhancing efficiency and reliability.

136

What network engineering skills do you possess?

Reference answer

As part of your network engineer interview preparation, itâ€™s important you can communicate to the interviewer the various network engineering skills you possess, as this is likely to be asked during the interview. When answering this question, you could mention the more technical skills youâ€™re equipped with, like your ability to troubleshoot hardware and software various types of network infrastructure issues as well as soft skills like organisational skills and your ability to manage projects on time. Hereâ€™s one response you could give when answering these types of network engineer interview questions: â€œI have the technical, analytical, and problem-solving skills to troubleshoot network problems and resolve issues quickly and efficiently with little to no downtime for the end user.â€

137

Where do your strengths lie with wireless network engineering? Where do you want to improve?

Reference answer

This question encourages self-assessment of technical strengths and areas for growth within wireless network engineering.

138

What are customer service interview questions and answers?

Reference answer

Customer service interview questions and answers with copy-and-adapt templates, weak-answer examples, and role-specific versions for retail, hospitality.

139

Which encryption type does WPA2 use?

Reference answer

WPA2 uses AES (Advanced Encryption Standard) encryption.

140

What is a Wi-Fi hotspot?

Reference answer

A hotspot is a physical location that provides internet access using Wi-Fi technology.

141

How does 5G OSS facilitate network automation?

Reference answer

Network automation is a crucial feature of 5G OSS, streamlining operations and enhancing efficiency. 5G OSS facilitates network automation by leveraging Artificial Intelligence, Machine Learning, and advanced analytics. Automation in OSS expedites routine tasks, optimises resource allocation, and proactively addresses issues, ensuring a responsive and agile network infrastructure.

142

Differentiate OSI Reference Model with TCP/IP Reference Model

Reference answer

| OSI Reference Model | TCP/IP Reference Model | |---|---| | 7 layered architecture | 4 layered architecture | | Fixed boundaries and functionality for each layer | Flexible architecture with no strict boundaries between layers | | Low Reliability | High Reliability | | Vertical Layer Approach | Horizontal Layer Approach |

143

Describe your experience using network monitoring tools to maintain network uptime and performance.

Reference answer

I have experience using network monitoring tools like Nagios, Zabbix, and SolarWinds to maintain network uptime and performance. My primary approach involves configuring these tools to proactively monitor critical network devices (routers, switches, firewalls, servers) and services using protocols like SNMP, ICMP, and TCP port checks. I set thresholds and alerts for metrics like CPU utilization, memory usage, interface bandwidth, latency, and packet loss. When an alert is triggered, I investigate the issue by analyzing the relevant metrics and logs provided by the monitoring tool. This helps me quickly identify the root cause, such as a saturated link, a failing device, or a misconfigured service. Based on the diagnosis, I take corrective actions, which might include restarting services, reconfiguring network devices, or escalating the issue to a higher-level support team. Furthermore, I use the historical data collected by these tools to identify trends, predict potential bottlenecks, and proactively optimize network performance.

144

What are wireless network channels and what is their purpose?

Reference answer

Wireless network channels are specific frequency ranges within the broader Wi-Fi bands (2.4 GHz and 5 GHz) used to transmit data. Their purpose is to reduce interference and overlap between multiple networks operating in the same area.

145

How do you troubleshoot network issues?

Reference answer

Troubleshooting network issues is kind of like playing detective - you have to follow the clues to find the root cause. The first step is typically to identify the symptoms. Is the issue lack of connectivity? Slow network speeds? Intermittent connection drops? Once the symptoms are clear, the next step is usually to isolate the problem. Start by checking the physical connections - are all cables and devices properly connected? If everything looks good there, you can use software tools to check on the health of the network. For example, you could use the ping command to check if a particular device is reachable, or use traceroute to see if network packets are moving through the network as expected. Once you've identified where the problem seems to be coming from, next comes resolving it. This might involve resetting a router, changing a faulty cable, updating network drivers, adjusting network settings, or even contacting your Internet Service Provider if the problem is out of your control. After implementing a fix, it's crucial to verify if the issue is truly resolved by monitoring the network's performance. And remember, documentation is key! Keeping a record of what steps were taken can be a lifesaver for resolving similar issues in the future or handing off to other team members.

146

Describe a complex network issue you encountered. How did you resolve it?

Reference answer

Assessment: The candidates must have problem-solving skills and the ability to apply technical knowledge to real-world scenarios. Red flags: Inability to provide a specific example or a lack of depth in the explanation may indicate limited experience in troubleshooting complex network issues.

147

What is a DNS server and how does DNS resolution work?

Reference answer

A DNS (Domain Name System) server's primary function is to translate human-readable domain names (like www.example.com ) into IP addresses (like 192.0.2.1 ), which computers use to identify each other on a network. This translation process is called DNS resolution. The resolution process generally works as follows: 1. A user types a domain name into their browser. 2. The browser queries a DNS resolver (often provided by the user's ISP). 3. The resolver recursively queries other DNS servers, starting with root servers, then top-level domain (TLD) servers (like .com ), and eventually authoritative name servers for the specific domain, until it finds the IP address associated with the domain name. 4. The resolver returns the IP address to the browser. 5. The browser then uses the IP address to connect to the web server hosting the website. DNS servers also cache responses to improve performance and reduce latency for future requests.

148

What are the main types of network security threats?

Reference answer

Main types of network security threats include: ● Viruses: Malicious software that can infect and spread through files and systems. ● Worms: Self-replicating malware that spreads across networks. ● Trojan Horses: Malicious software disguised as legitimate applications. ● Phishing: Fraudulent attempts to obtain sensitive information by pretending to be a trustworthy entity. ● Denial of Service (DoS): Attacks that overwhelm a network or service to render it unavailable.

149

Identify the primary components of the 5G Core Network (CN).

Reference answer

The 5G Core Network comprises the following key elements: a) Access and Mobility Management Function (AMF) b) Session Management Function (SMF) c) User Plane Function (UPF) d) Network Exposure Function (NEF) Each component plays a distinct role in managing network functions and ensuring seamless connectivity.

150

What commands are used to check network configuration on your computer?

Reference answer

To check the network configuration on your computer, several basic commands are commonly used. On Windows, ipconfig is used to display IP address, subnet mask, default gateway, and DNS server information. ipconfig /all provides even more detailed information. On Linux and macOS, ifconfig (though sometimes deprecated in favor of ip ) can show similar network interface details. ip addr is the modern replacement. ping is a universal command to test connectivity to a specific host. traceroute (Linux/macOS) or tracert (Windows) can trace the route packets take to reach a destination. netstat (though also sometimes deprecated) or ss provides information about network connections, listening ports, and routing tables. nslookup or dig is for querying DNS servers to resolve domain names to IP addresses.

151

What is a channel in wireless networking?

Reference answer

A channel is a specific frequency band used for wireless communication. Wireless networks operate on different channels to avoid interference. Choosing the right channel is important for optimal performance.

152

What is a mesh network and how does it work?

Reference answer

A mesh network consists of multiple interconnected nodes that work together to provide seamless Wi-Fi coverage over a large area. Each node communicates with the others, forming a robust and flexible network. This setup eliminates dead zones and ensures consistent connectivity by dynamically routing data through the best available path.

153

Describe the deployment process of a 5G network.

Reference answer

5G network deployment involves meticulous planning, site preparation, equipment installation, and optimisation. The process encompasses radio access network deployment, core network integration, and thorough testing to ensure seamless connectivity and optimal performance.

154

Define the functionality of the OSI session layer.

Reference answer

The OSI session layer provides the protocol and means for two devices on the network to communicate with each other by keeping a session. It is responsible for session establishment, management of session time information exchange, and tear-down process based on session termination.

155

What are common network troubleshooting tools and techniques?

Reference answer

Common network troubleshooting tools include ping , traceroute (or tracert on Windows), nslookup (or dig on Linux/macOS), ifconfig (or ipconfig on Windows), and tcpdump (or Wireshark for a GUI). These tools help determine network reachability, route tracing, DNS resolution, IP configuration, and packet capture for detailed analysis. Techniques involve a systematic approach like the OSI model, starting from the physical layer (checking cables and connectivity) up to the application layer. Other techniques include checking IP configuration, DNS settings, routing tables, and firewall rules. Isolating the problem by testing connectivity between different points in the network and analyzing error messages are also helpful.

156

What are the main factors affecting Wireless Network?

Reference answer

Factors Include: Distance, obstructions, wireless standard, signal sharing, and network interference.

157

What are some common networking protocols you've heard of?

Reference answer

Some common networking protocols I've heard of include HTTP (Hypertext Transfer Protocol) and HTTPS (HTTP Secure) which are used for web communication. TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) are fundamental transport layer protocols. TCP provides reliable, ordered, and error-checked delivery, while UDP is faster but unreliable. Other protocols include DNS (Domain Name System) for translating domain names to IP addresses, SMTP (Simple Mail Transfer Protocol) for sending emails, and FTP (File Transfer Protocol) for transferring files between a client and server. SSH (Secure Shell) is used for secure remote access to systems. Also, I am familiar with IP (Internet Protocol) which is a core protocol for routing packets across networks, and Ethernet, a standard for local area networks (LANs).

158

How do you secure VoIP communications?

Reference answer

To secure VoIP communications, encrypt the traffic, use strong authentication for VoIP devices, regularly update and patch systems, monitor for unusual activities, and segment the network to isolate VoIP traffic.

159

What is a mesh Wi-Fi system?

Reference answer

A mesh Wi-Fi system uses multiple access points that connect to each other wirelessly, creating a self-healing network that provides better coverage and performance compared to traditional single-router setups.

160

Describe your experience with TLS/SSL and IPsec protocols.

Reference answer

I have experience working with TLS/SSL and IPsec protocols in several projects. With TLS/SSL, I've configured web servers (like Apache and Nginx) to use HTTPS, including generating and installing certificates, and ensuring proper cipher suite configurations for secure communication. I've also used libraries like OpenSSL in applications to establish secure connections to APIs. Regarding IPsec, I have experience configuring VPNs using IPsec for secure site-to-site and remote access connections. This involved setting up security policies, defining encryption algorithms (like AES), and authentication methods (like pre-shared keys and certificate-based authentication). I understand the key components like AH, ESP, and IKE and their roles in securing network traffic.

161

How does a wireless mesh network work?

Reference answer

A wireless mesh network consists of multiple access points that communicate with each other to form a self-healing, redundant network. Each AP acts as a node that relays data, extending coverage and improving network resilience.

162

What are some common mistakes you've seen when setting up wireless networks?

Reference answer

This question tests the candidate's practical knowledge of common pitfalls, such as poor placement, misconfigured security, or inadequate capacity planning.

163

Describe the TCP/IP Model.

Reference answer

The TCP/IP model, the backbone of the internet, consists of 4 layers: - Network Access Layer: Manages physical connections. - Internet Layer: Handles routing using IP. - Transport Layer: Uses TCP/UDP for reliability and speed. - Application Layer: Runs protocols like HTTP, SMTP, and FTP.

164

What is a VPN and why do people use it?

Reference answer

A VPN (Virtual Private Network) creates a secure, encrypted connection over a less secure network, like the public internet. It essentially masks your IP address and encrypts your data, making it harder for others to monitor your online activity. People use VPNs for several reasons. These reasons may include protecting their privacy while using public Wi-Fi, bypassing geographical restrictions to access content not available in their region, and enhancing security when transmitting sensitive data. Also, some may want to prevent their ISP from tracking their browsing history or to circumvent censorship.

165

What are the advantages of a client-server network?

Reference answer

Client-server networks offer several advantages. Centralized resource management is a key benefit, allowing for easier administration of files, applications, and security policies. This also enhances data security through controlled access and backups. Furthermore, client-server architecture supports scalability. As the number of users or devices increases, the server infrastructure can be upgraded to handle the increased load, ensuring consistent performance. Client-server networks also allow for a clear separation of duties, allowing for the design of more modular and testable applications where business logic is handled on the server and the client handles the user interface.

166

A user reports "limited connectivity" on their PC. How will you troubleshoot this issue?

Reference answer

You can troubleshoot this issue by: - Checking the physical connectivity (cable/Wi-Fi) - After that, you should verify the IP Address using the command "ipconfig /all" - Next, check whether the PC received a valid IP address, Subnet mask, default gateway, and DNS server. If the IP starts with 169.254.x.x, it clearly shows a DHCP failure. If it is so, then you should: - Get the IP address renewed - Test ping to the gateway - Check the availability of the DHCP server - Verify switch port status

167

Describe the key components of a communication system.

Reference answer

A communication system consists of a source (generating the message), a transmitter (encoding and modulating the signal), a channel (medium for transmission), a receiver (demodulating and decoding), and a destination (consuming the message). Antennas are used at both transmitter and receiver for wireless systems.

168

What is encryption and how is it used in network security?

Reference answer

Encryption is the process of converting plaintext into a coded format to prevent unauthorized access. It is used in network security to protect sensitive data during transmission and storage, ensuring that even if data is intercepted, it cannot be read without the proper decryption key.

169

What is your approach to incident response?

Reference answer

My approach to incident response involves several key steps: ● Preparation: Develop and maintain an incident response plan with defined roles and procedures. ● Identification: Detect and confirm the occurrence of a security incident using monitoring tools and alerts. ● Containment: Take immediate steps to contain the incident and prevent further damage. ● Eradication: Remove the root cause of the incident and ensure that any malicious artifacts are cleaned up. ● Recovery: Restore affected systems and services to normal operation while validating that the incident has been fully resolved. ● Lessons Learned: Conduct a post-incident review to analyze what happened, assess the response, and improve future incident response efforts.

170

How do you implement and manage ACLs?

Reference answer

Implementing and managing ACLs involves defining rules that control network traffic based on IP addresses, protocols, or ports. For this, network engineers need to: Determine the security policies and requirements; Create ACL entries specifying permitted or denied traffic types; Apply these ACLs to network interfaces or devices to enforce the rules; Regularly review and update ACLs to adapt to changing security needs and ensure they are not overly restrictive or permissive. Proper documentation and testing are essential to ensure ACLs function as intended without disrupting legitimate network traffic.

171

What kind of protocol is OSPF, and how does it differ from BGP?

Reference answer

OSPF (Open Shortest Path First) is a link-state routing protocol used within a single autonomous system. It uses Dijkstra's algorithm to calculate the shortest path and is different from BGP in its scope and functionality.

172

What is a clear 4-part formula for answering the 'how do you handle conflict' interview question?

Reference answer

A clear 4-part formula for answering the how do you handle conflict interview question, with timed sample answers, weak-vs-strong phrasing, and ways to adapt.

173

What is multicast and how does it work?

Reference answer

Multicast is a network addressing method for delivering information to a group of destination computers simultaneously within a network. It bridges the gap between unicast (one-to-one) and broadcast (one-to-all) communication modes. In multicast communication, the source sends a single set of packets which is then delivered to a group of recipients, identified by a multicast group address, thereby reducing network traffic and ensuring more efficient data distribution when sending the same data to multiple recipients. A typical use case for multicasting is streaming media, such as video or audio broadcasts. If a server is streaming a live event, it would send out a single stream of information - let's say one video feed - to the multicast group address. Any device that wants to view the event would then join the multicast group and receive the data. The multicast process is managed and optimized through protocols like Internet Group Management Protocol (IGMP) for managing group membership and Protocol Independent Multicast (PIM) for routing the multicast traffic to the interested receivers. These mechanisms ensure efficient data delivery without overloading the network or the source device.

174

What is the purpose of using an antenna in a wireless network?

Reference answer

Antennas are used to transmit and receive wireless signals between devices. They convert electrical signals into radio waves and vice versa, enabling communication over the air. Different types of antennas (e.g., omnidirectional, directional) are used based on the network design and coverage requirements.

175

What relevant network engineering qualifications do you have?

Reference answer

Here you can list any qualifications or certifications youâ€™ve gained on your network engineering journey, whether through university degrees, network engineering courses or an apprenticeship course youâ€™ve completed. Although you may put all this down on your CV, this network engineer question allows you to expand on the qualifications youâ€™ve achieved, why you enrolled on these courses, and what you learned.

176

Why is network documentation crucial?

Reference answer

Network documentation is crucial for several reasons. It serves as a central repository of information about the network's design, configuration, and operation, making troubleshooting and maintenance significantly easier. Accurate and up-to-date documentation allows network administrators to quickly identify problems, understand the impact of changes, and plan for future growth. Without proper documentation, tasks like onboarding new engineers, responding to outages, or implementing security measures become substantially more difficult and time-consuming. Comprehensive documentation reduces reliance on individual tribal knowledge, ensuring that the network can be managed effectively even in the absence of specific personnel. It also supports compliance efforts by providing an audit trail of network configurations and changes.

177

Wireless networking, or Wi-Fi, can be used to connect computers in a home, and many cities are using technologies to offer free or low cost internet access to residents, what is another name for Wi-Fi?

Reference answer

- IEEE 802.11 is the official name for WIFI wireless specification. It is composed of more than 20 different standards (802.11a, 802.11b, etc), each of which have their own defining characteristics. Since not all standards operate on the same frequency, not all 802.11 devices are compliant with one another, so be sure to consider the compatibility when making your purchasing decision. So this is an alternative name for Wi-Fi which suits all the properties of the Wi-Fi and functioning as well. - Wireless networking hardware requires the use of underlying technology that deals with radio frequencies as well as data transmission. The most widely used standard is 802.11 produced by the Institute of Electrical and Electronic Engineers (IEEE). This is a standard defining all aspects of Radio Frequency Wireless networking.

178

Can you describe the OSI model and its layers?

Reference answer

The OSI (Open Systems Interconnection) model is a seven-layer framework that standardizes the functions of a network into layers: Physical, Data Link, Network, Transport, Session, Presentation, and Application. Each layer has specific roles and responsibilities in the communication process. - Which layer is the Application Layer, and what is its function? The Application Layer is the topmost layer, providing network services directly to applications. It handles protocols and data that applications use to communicate over the network. - Which layers are considered the hardware or network support layers? The Data Link Layer and Physical Layer are considered hardware or network support layers. They deal with the physical transmission of data and error detection/correction.

179

What are the messages exchanged between STA and AP in WLAN? Explain the function of each.

Reference answer

There are various messages exchanged between a Station (STA) and an Access Point (AP) in a WLAN network for various purposes, such as establishing a connection, data transfer, terminating the connection, and more. Access points are devices that help extend wired networks with wireless capabilities. The main WLAN MAC messages are listed below with their main functions. - Association request: This is sent by STA to AP to obtain association after authentication is done. - Association response: This message is sent by AP in response to the received association request. - Probe request: It is used to find out AP in the WLAN network. - Probe response: It contains station (STA) parameters as well as data rates. - Beacon: It is used by AP to announce the start of a CF (Contention Free) period. - Disassociation: Used to announce the break-up of an existing association between peers in a WLAN network. - Authentication: These packets are used by STA to request authentication. - De-Authentication: Used by an authenticated station to announce that the receiver no longer needs to be authenticated. - RTS/CTS: Used for the initial handshake between WLAN peers. - ACK: Indicates the receipt of transmitted data whether reached on the other side or not. - CF end: It indicates the end of CFP (contention-free period).

180

How do you secure a guest wireless network?

Reference answer

To secure a guest wireless network: - - Use a separate VLAN for guest traffic to isolate it from the main network. - Implement WPA2 or WPA3 encryption. - Require guest users to authenticate via a captive portal. - Restrict access to internal resources and monitor guest network activity.

181

What is the position of the transmission media in the OSI model?

Reference answer

In the OSI model, transmission media supports layer-1(Physical layer).

182

What is DNS and why is it important?

Reference answer

DNS, or Domain Name System, translates human-readable domain names (like google.com) into IP addresses (like 142.250.185.142), which computers use to identify each other on the internet. Think of it as the internet's phone book. It's important because without DNS, you'd have to remember and type in IP addresses every time you wanted to visit a website. DNS makes the internet user-friendly by allowing us to use easy-to-remember domain names. It also provides redundancy and allows websites to change IP addresses without disrupting service, since the DNS record can be updated to point to the new address.

183

How would you be able to distinguish the IP class of a given IP address?

Reference answer

By taking a gander at the principal octet of some random IP address, you can recognize whether it's Class A, B, or C. On the off chance that the principal octet starts with a 0 bit, that address is Class A. On the off chance that it starts with bits 10, that address is a Class B address. On the off chance that it starts with 110, it's a Class C network.

184

What is a realistic mock transcript of 25 motivational interview questions?

Reference answer

A realistic mock transcript of 25 motivational interview questions, with candidate answers, interviewer follow-ups, and revised responses that sound confident.

185

What is an IP address (Internet Protocol address) and why are IP addresses crucial?

Reference answer

An IP address (Internet Protocol address) is a numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication. It serves two main functions: identifying the host or network interface and providing a location addressing. Think of it like a postal address for your computer on the internet. IP addresses are crucial because they enable devices to find each other and exchange data. Without IP addresses, data packets wouldn't know where to go, making communication across the internet impossible. Each packet needs a destination IP address to ensure it reaches the correct recipient.

186

What is Piggy Backing?

Reference answer

The network is the communication between two nodes that are interconnected by each other to share resources and data. But when we think about acknowledgment in between two-way communications there were several issues are raised, in that network needs to utilize a lot of bandwidth, and there again needed solutions for the same. So, there is a thing which is Piggybacking, which is used when we want to transfer data in two-way communication, and there is no need to send special acknowledgment with the frame.

187

What is a transparent bridge?

Reference answer

Transparent Bridge: A transparent bridge automatically maintains a routing table and updates tables in response to maintaining changing topology. The transparent bridge mechanism consists of three mechanisms: - Frame forwarding - Address Learning - Loop Resolution The Transparent bridge is easy to use. Install the bridge and no software changes are needed in the hosts. In all the cases, transparent bridges flooded the broadcast and multicast frames.

188

What is the importance of twisting in the twisted-pair cable?

Reference answer

The twisted-pair cable consists of two insulated copper wires twisted together. The twisting is important for minimizing electromagnetic radiation and external interference.

189

How does Wi-Fi work and what are the key security protocols?

Reference answer

Wi-Fi allows devices to connect to a network wirelessly using radio waves. A wireless router broadcasts a Service Set Identifier (SSID), which is the network name, and devices within range can detect and connect to it. The router acts as a bridge, translating data between the wireless devices and the wired network or internet connection. Protocols like 802.11a/b/g/n/ac/ax define the standards for Wi-Fi communication, specifying data rates, frequencies, and other parameters. Security protocols are crucial for protecting wireless networks. WPA2 (Wi-Fi Protected Access 2) is a common protocol that uses AES encryption, while WPA3 is a more recent and secure standard. These protocols use a pre-shared key (PSK) or Enterprise authentication (like RADIUS) to grant network access. Older protocols like WEP are considered insecure and should not be used. MAC address filtering and disabling SSID broadcasting are additional (but less reliable) security measures.

190

Why do we need the pop3 protocol for e-mail?

Reference answer

Need of POP3: The Post Office Protocol (POP3) is the most widely used protocol and is supported by most email clients. It provides a convenient and standard way for users to access mailboxes and download messages. An important advantage of this is that the mail messages get delivered to the client's PC and they can be read with or without accessing the web.

191

Explain the WLAN physical layer frame as per 802.11a?

Reference answer

WLAN has physical layer frame formats that differ in 11a, 11b, 11g, 11n, and 11ac. They all have three generic fields: preamble, header, and data payload (PSDU). The preamble carries STF (short training field) and LTF (long training field) used for front-end synchronization. Front-end synchronization includes time offset estimation and correction, frequency offset estimation and correction, and channel estimation and equalization. The header carries two important parameters: rate and length. Rate specifies the modulation-code rate of the data payload part, and the length field specifies the length of the data payload in units of OFDM symbols.

192

Differentiate between static IP addressing and dynamic IP addressing.

Reference answer

Static IP Addressing: IP address manually assigned to a device or network; manually configured by network administrator; remains constant unless manually changed; requires manual management and updates; potentially more secure as address doesn't change; less flexible for large networks; may incur additional costs for each static IP address. Dynamic IP Addressing: IP address automatically assigned by a DHCP server; automatically assigned upon device connection; can change over time, depending on DHCP lease duration; less administrative overhead due to automatic allocation; may introduce security risks due to changing addresses; more flexible for large networks due to dynamic allocation; typically, more cost-effective due to shared IP resources.

193

How do you use configuration management tools like Ansible, Puppet, or Chef in networking?

Reference answer

For this, network engineers and administrators use tools like Ansible, Puppet, or Chef to define the desired state of network devices and push configurations to devices, ensuring consistency and compliance. Automation reduces manual errors, speeds up deployment, and simplifies management across multiple devices.

194

What is network segmentation and micro-segmentation, and what are their benefits?

Reference answer

Network segmentation divides a network into smaller, isolated segments, often based on function, risk level, or compliance requirements. This limits the blast radius of a security breach. Micro-segmentation takes this further, isolating individual workloads or applications, creating even more granular security boundaries. Think of network segmentation as dividing a house into rooms, and micro-segmentation as putting locks on each cabinet in those rooms. The benefits of both include reduced attack surface, improved threat containment (preventing lateral movement), enhanced compliance by isolating sensitive data, and simplified security management by applying targeted policies to specific segments. Micro-segmentation offers more precise control and visibility, making it easier to detect and respond to threats targeting specific applications or services.

195

What is a VPN?

Reference answer

A VPN stands for Virtual Private Network, a technology that allows a secure tunnel to be created across a network like the Internet. For example, VPNs enable you to set up a secure dial-up connection to a remote server, masking your IP geolocation to protect your identity and maintain privacy online.

196

What is the Role of Threat Intelligence in Security Operations?

Reference answer

It helps identify potential threats in advance, which can be obtained through intelligence services or communities. It is used in strategy formulation and incident response.

197

How would you put in place network security procedures?

Reference answer

Ensuring networks are protected and secured from the various threats out there in the ever-evolving tech landscape, now more than ever, businesses expect network engineers to have the skills to protect their organisation and that of their clients from potential attacks that could pose financial and reputational harm to a company. Therefore, itâ€™s highly likely youâ€™ll be asked this type of network engineer interview question and hereâ€™s how you can answer it. â€œThere are multiple effective approaches to achieve ensure your network is secure. First, I would ensure that all work computers and devices are installed with a reliable and up-to-date anti-virus programme. Secondly, Iâ€™d recommend setting up and configuring appropriate firewalls to bolster network security. I would also consider implementing user authentication protocols to help enhance the protection of the network. By combining these measures, a highly secured network can be established.â€ If youâ€™re entering a more entry-level network engineer job, you may only be expected to demonstrate your knowledge of network security. So at the very least, itâ€™s worth having an understanding of this area of network engineering.

198

What is TCP/IP?

Reference answer

TCP/IP is short for Transmission Control Protocol/Internet Protocol. This is a bunch of convention layers that are intended to make information trade conceivable on various sorts of PC network, otherwise called a heterogeneous network.

199

What is a zone-based firewall?

Reference answer

A Zone-based firewall is an advanced method of stateful firewall. In a stateful firewall, a stateful database is maintained in which the source IP address, destination IP address, source port number, and destination port number are recorded. Due to this, only the replies are allowed i.e. if the traffic is Generated from inside the network then only the replies (of inside network traffic) coming from outside the network are allowed. Cisco IOS router can be made firewall through two methods: - By using CBAC: create an access list and apply it to the interfaces keeping in mind what traffic should be allowed or denied and in what direction. This has an extra overhead for the administrator. - Using a Zone-based firewall. For more details please refer Zone-based firewall article.

200

Describe the Purpose and Working Principle of STP.

Reference answer

STP (Spanning Tree Protocol) prevents network loops in Layer 2 networks by logically blocking certain paths. It involves selecting a root bridge, root ports, and designated ports while blocking non-designated ports to maintain a loop-free topology.

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