Common Interview Questions for Wireless Network Analysts

1

What is a DDoS Attack and How is it Prevented?

Reference answer

A DDoS attack floods a target network or server with massive data traffic, rendering it non-functional. Prevention includes bandwidth expansion, firewalls, IPS/IDS installations, and connection rate limiting.

2

What are some common wireless network management tools?

Reference answer

Common tools include: - Wireshark: A network packet analyzer for capturing and analyzing network traffic. - NetStumbler: A tool for discovering and mapping wireless networks. - InSSIDer: Another tool for network discovery and channel analysis. - Wireless network controllers: Provide centralized management for multiple access points.

3

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

Reference answer

Public and private IP addresses refer to the type of Internet Protocol (IP) addresses that devices can be assigned in a network. A public IP address, as the name suggests, is an IP address that is uniquely identifiable across the internet. It's the principal address that your Internet Service Provider (ISP) assigns to your router or modem. It's visible to the entire internet, much like your physical home address. Private IP addresses, on the other hand, are used within internal networks and can't be directly accessed over the internet. These are typically used for local devices within your home or work network, such as your desktop, laptop, or smartphone. While thousands of devices might have the same private IP, they each have a unique public IP that's used for communication outside their local network. So, by analogy, if the internet was a city, then your public IP would be your home's street address, visible to everyone, and your private IP would be like your bedroom's location within your home, known only to the residents.

4

What is the difference between Wi-Fi and Ethernet?

Reference answer

Imagine your phone connecting to the internet. Wi-Fi is like using the phone's speaker to talk to someone – it's wireless. Ethernet is like using a wired headset. So, Wi-Fi is a wireless way to connect devices to the internet using radio waves. Ethernet is a wired connection, where you plug a cable directly from your device (like a computer) into your internet router or modem. Ethernet is generally faster and more reliable than Wi-Fi, but Wi-Fi is more convenient since you don't need cables.

5

Describe the TCP/IP Reference Model

Reference answer

It is a compressed version of the OSI model with only 4 layers. It was developed by the US Department of Defence (DoD) in the 1980s. The name of this model is based on 2 standard protocols used i.e. TCP (Transmission Control Protocol) and IP (Internet Protocol).

6

What are the different types of networks?

Reference answer

Mainly there are four types of networks. These are: 1. Personal Area Network (PAN) The Personal Area Network (PAN) is considered to be the fundamental form of computer networking. This network is limited to an individual user, meaning that the exchange of information among computer devices is limited only to the user's personal workspace. The PAN technology allows communication between devices within a range of 1 to 100 meters from the user. The transmission speed is relatively high, and its maintenance is simple and cost-effective. 2. Local Area Network (LAN) LAN is a type of computer network that connects devices within a limited geographic area, such as a home, office, or school. LANs allow users to share resources, such as files, printers, and internet access, among the connected devices. One of the basic examples of Local Area Network (LAN) is a printer connected to a computer. The maximum range of the system is 1-10 kilometers, and its transmission speed is significantly high. 3. Metropolitan Area Network (MAN) The Metropolitan Area Network (MAN) is a network type that covers the network connection of an entire city or connection of a small area. The area covered by the network is connected using a wired network, like data cables. This network mainly uses FDDI, CDDI, and ATM as the technology, ranging from 5km to 50km. Its transmission speed is average. It isn't easy to maintain, and it comes with a high cost. 4. Wide Area Network (WAN) WAN is a network that connects devices over a large geographical area, such as different cities or countries. WANs typically use public or leased telecommunication lines to transmit data. Examples of WANs are the Internet, corporate networks, and satellite networks. In most cases, the connection is established through wireless means and relies on radio towers for transmission. WAN is a collection of Local Area Networks (LANs) that are connected with each other over a distance above 50 kilometers.

7

How do you keep updated with network engineering trends?

Reference answer

Top talent in this space always keeps themselves up-to-date with the latest network engineering trends, including the latest technology developments, protocols and best practices. An interviewer may ask you this question to evaluate how interested you are in progressing in network engineering, so be sure to brush up on the latest trends before the interview. Here's how to prepare for network engineer interview questions like this one: "I recognise that staying up-to-date with the latest network engineering trends, products, and technologies is essential to my career, especially given the rapid pace of the IT industry. To achieve this, I actively engage in various online professional groups where we exchange ideas and explore new concepts. I also stay informed by subscribing to multiple podcasts and attending an annual IT conference. Additionally, I try to enrol on the latest courses and certifications and complete them in my own time to keep my knowledge of network engineering up-to-date."

8

Talk me through a project where the requirements changed after it was already underway. How did this affect the project and what solutions did you find?

Reference answer

This question assesses adaptability and problem-solving when facing changing project requirements in wireless network engineering.

9

What are the different types of networks?

Reference answer

Whether youâ€™re an experienced senior network engineer or coming into the industry as an entry-level network engineer, there are various types of networks to be aware of. These types of networks include: - WANs (wide area networks) - LANs (local area networks) - MANs (metropolitan area networks) - PAN (personal area network) - GANs (global area networks) - WLAN (wireless local area network) - SAN (storage area network) - DAN (desk area network) - CAN (campus area network) - VoIP (voice over internet protocol). During an interview, your potential future employer may ask you to list some of the types of networks listed above or provide detail on a specific type of network. Hereâ€™s how to answer the question if the interviewer asks you to describe what WAN is. â€œWAN, which stands for Wide Area Network, refers to the interlinking of computers and devices across vast geographical distances. It facilitates the connection of networks spread across different regions and countries, enabling seamless communication, and data exchange.â€ The answer weâ€™ve provided above can be tailored to any type of network.

10

What are the types of modulation used in wireless systems?

Reference answer

Common modulation types include Amplitude Modulation (AM), Frequency Modulation (FM), Phase Modulation (PM), and digital schemes like QPSK, 16-QAM, 64-QAM, and 256-QAM, which balance data rate and robustness against noise.

11

What is Symmetric and Asymmetric Encryption?

Reference answer

- Symmetric Key Encryption: Encryption is a process to change the form of any message in order to protect it from reading by anyone. In Symmetric-key encryption the message is encrypted by using a key and the same key is used to decrypt the message which makes it easy to use but less secure. It also requires a safe method to transfer the key from one party to another. - Asymmetric Key Encryption: Asymmetric Key Encryption is based on public and private key encryption techniques. It uses two different keys to encrypt and decrypt the message. It is more secure than the symmetric key encryption technique but is much slower. For more details please refer difference between symmetric and asymmetric encryption articles.

12

What is a VPN?

Reference answer

VPN implies Virtual Private Network, an innovation that permits a safe passage to be made across a network like the Internet. For instance, VPNs permit you to set up a safe dial-up association with a far-off worker.

13

What are the key differences between cloud networking and on-premises networking?

Reference answer

Cloud networking and on-premises networking differ significantly in several aspects. Traditional on-premises networking relies on physical hardware (routers, switches, firewalls) owned and managed by the organization within its physical location. Cloud networking, on the other hand, utilizes a virtualized infrastructure provided by a cloud service provider (CSP). This means network resources are provisioned and managed programmatically via software. Key differences include scalability (cloud networks scale dynamically), cost (cloud uses a pay-as-you-go model potentially reducing capital expenditure), management (cloud networking is often managed by the CSP simplifying operations), and location dependency (on-premises is tied to a physical location, while cloud is globally accessible). Additionally, cloud networking often incorporates advanced features like software-defined networking (SDN) and network function virtualization (NFV) for improved agility and automation which may not be as easy or cost-effective to implement on-premises.

14

How do you stay current with the latest networking technologies and trends?

Reference answer

I regularly read publications like Network World and follow key influencers in the networking field on LinkedIn. I also participate in webinars and recently completed my CCNP certification. Staying updated helped me implement a new SD-WAN solution at my last job, significantly improving network flexibility and reducing costs. Networking with peers at industry conferences has also provided insights into emerging trends.

15

What is SQL Injection, and How Can It Be Prevented?

Reference answer

SQL injection exploits input data to manipulate SQL queries and control databases. Preventive measures include input validation, using parameterized queries, restricting database permissions, and conducting code audits.

16

What is EIGRP?

Reference answer

Enhanced Interior Gateway Routing Protocol is Cisco-proprietary, combining link-state and distance-vector properties. It uses the DUAL algorithm for fast convergence.

17

How do you handle wireless network capacity planning?

Reference answer

Capacity planning involves assessing current and future network demands, analyzing user density, and determining the number of access points needed. It includes evaluating bandwidth requirements, coverage areas, and potential growth to ensure the network can handle anticipated loads.

18

What is POP3?

Reference answer

Post Office Protocol3 (POP3) retrieves email from a server to a local client, operating over TCP/IP. It's efficient but lacks features like folder synchronisation. POP3 uses a download-and-delete model, removing messages from the server upon retrieval. IMAP has largely supplanted it due to its broader functionality in modern email systems.

19

How do you stay current with the latest trends and technologies in network security?

Reference answer

Staying current with trends is crucial in network security. Some of the latest trends and technologies include: ● Zero Trust Security: A model that assumes no entity, whether inside or outside the network, should be trusted by default. ● Artificial Intelligence and Machine Learning: Enhancing threat detection and response through advanced algorithms and automated analysis. ● Extended Detection and Response (XDR): Integrating multiple security solutions to provide a unified approach to threat detection and response. ● Security Automation: Automating routine security tasks to improve efficiency and response times.

20

Can you define NAT?

Reference answer

NAT stands for Network Address Translation. This is for IP networks that are using unregistered IP addresses. NAT enables them to connect to the internet. In this process, a public address is assigned to a system within a private network. NAT operates using a router and converts the private addresses into legal addresses. It is also used for securing networks by limiting the number of IP addresses a company can use within a network.

21

How do you balance network security with performance requirements?

Reference answer

In my previous position with Bell Canada, I implemented a comprehensive firewall strategy that included VPNs and intrusion detection systems while ensuring bandwidth was optimized for critical applications. I conducted regular training sessions for staff on phishing and other security threats, which decreased security incidents by 40%. Balancing security and performance is about continuous evaluation and adapting to emerging threats, which I prioritize.

22

What is Network Automation?

Reference answer

Network automation uses tools like Python, Ansible, or Cisco DNA Center to perform configurations, audits, and deployments automatically.

23

Define uRLLC and its relevance in 5G NR.

Reference answer

Ultra-Reliable Low Latency Communications (uRLLC) is a critical aspect of 5G NR, catering to applications with stringent requirements. uRLLC ensures ultra-reliable and low-latency communication, making it indispensable for applications demanding instantaneous response times, such as industrial automation, remote surgery, and mission-critical services. Its high reliability sets the stage for revolutionary advancements in various industries.

24

Which frame has SSID ?

Reference answer

Beacon, Directed Probe request, Probe Response, Assoc Req, Re-association Req

25

How do you analyze network traffic patterns?

Reference answer

Analyzing network traffic patterns requires using tools like Wireshark, NetFlow analyzers, or network management software. With the help of software, network engineers: Collect and examine data on traffic volume, flow, sources, and destinations; Look for trends, spikes, or irregularities in the data; Use this analysis to identify potential issues and optimize performance.

26

What is IBSS, BSS, and ESS?

Reference answer

IBSS (Independent Basic Service Set) is an ad-hoc network without an access point. BSS (Basic Service Set) is a group of stations sharing an access point. ESS (Extended Service Set) is a group of access points connected to the same WLAN, allowing roaming.

27

What is subnetting and why is it used?

Reference answer

Subnetting divides a large network into smaller, more manageable subnetworks. It enhances network performance and security by reducing traffic and isolating segments. Subnetting also conserves IP addresses, making network management more efficient and scalable.

28

How do you troubleshoot network connectivity issues?

Reference answer

Troubleshooting network connectivity issues involves steps like checking physical connections, verifying IP addresses and subnet masks, using tools like ping and traceroute to isolate the problem, checking router and switch configurations, and reviewing firewall settings.

29

What is MIMO, SU-MIMO, MU-MIMO, Beamforming etc

Reference answer

These are some of the most common terms you will come across while reading content on 11n and 11ac. The books i have referenced have all you need on these concepts

30

Discuss Data Backup and Recovery Strategies in Network Security.

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Strategies include regularly backing up data, storing backups in different locations, testing recovery processes, and establishing an emergency recovery plan.

31

Can IP multicast be load-balanced?

Reference answer

No, because the IP multicast multipath command separates traffic, not balances traffic. Traffic coming from a source will be allowed only one way, even if the traffic far exceeds traffic coming from other sources.

32

Explain the concept of IP address in wireless networking.

Reference answer

An IP (Internet Protocol) address is a unique identifier assigned to each device connected to a network. It allows devices to communicate with each other and access internet resources.

33

How do you ensure high availability in a network?

Reference answer

High availability requires implementing redundancy and failover mechanisms. For this, they'd need to: Use multiple, redundant links and devices to eliminate single points of failure; Implement technologies like load balancing and clustering to distribute traffic evenly and handle failures; Make regular backups and have disaster recovery plans to restore services quickly.

34

What is the purpose of QoS (Quality of Service) in wireless networking?

Reference answer

QoS prioritizes network traffic based on application needs, ensuring that critical data, like video streaming or VoIP, receives priority and better performance. It helps manage bandwidth and improve the overall user experience.

35

Can you define OSPF?

Reference answer

OSPF stands for Open Shortest Path First. This is a link-state routing protocol that is used for identifying the best path for transferring data packets. This protocol is useful as it makes use of the network bandwidth efficiently.

36

Assess the impact of Network slicing on 5G OSS.

Reference answer

Operational Support Systems (OSS) play a vital role in managing and maintaining 5G networks. Network slicing impacts 5G OSS by introducing new complexities in resource management, service orchestration, and monitoring. OSS systems need to adapt to the dynamic nature of Network slicing to ensure efficient operations and deliver a seamless user experience.

37

Suppose you connect a new switch to a network, and the entire network starts flapping. What could be the reason for this?

Reference answer

An issue that can cause the entire network to flap is a Layer 2 loop. It can be caused by improper cabling or Spanning Tree issues. Some symptoms of this issue are: - Flapping of MAC Address - High broadcast traffic - The network will be very slow - CPU spikes on switches To troubleshoot the issue, you can: - Check the status of STP - Find the links that can be reduced - Verify BPDU exchange - And disconnect suspected loop links The commands you need: "show spanning-tree" "show mac address-table"

38

How do you monitor and analyze network traffic?

Reference answer

Network traffic monitoring and analysis are crucial for understanding performance, detecting anomalies, and optimizing resources. Tools like SNMP, NetFlow, and sFlow can collect traffic data, and analysis tools like nfdump and nfsen can visualize and analyze it.

39

What is a wireless firewall?

Reference answer

A wireless firewall is a security device that filters network traffic to prevent unauthorized access and protect the network from attacks.

40

What is the protocol and port no of DNS?

Reference answer

Protocol - TCP/UDP Port number- 53

41

How do you troubleshoot connectivity for voice and data on a large-scale infrastructure?

Reference answer

Troubleshooting begins with identifying the scope of the issue (single user, group, or entire site). For data, I would check physical connectivity (cables, ports), verify IP configuration (DHCP or static), test Layer 2 connectivity (ARP, VLAN membership), and then Layer 3 routing (ping, traceroute). For voice, I would check QoS configurations, codec compatibility, SIP trunk status, and latency/jitter using tools like Wireshark or VoIP-specific monitors. I would also review logs on switches, routers, and firewalls.

42

What is the difference between a hub and a switch?

Reference answer

A hub operates at the physical layer (Layer 1) of the OSI model and simply rebroadcasts any received data to all connected devices. This creates a collision domain, meaning only one device can transmit at a time without causing data collisions. A switch, on the other hand, operates at the data link layer (Layer 2) and uses MAC addresses to forward data only to the intended recipient. This creates separate collision domains for each port, allowing multiple devices to transmit simultaneously without collisions, resulting in improved network performance and security.

43

Explain the functioning of V2V communication in 5G.

Reference answer

Vehicle-to-Everything (V2X) communication, including V2V (Vehicle-to-Vehicle), is a pivotal aspect of 5G. V2V communication in 5G enables vehicles to exchange information in real time, enhancing road safety and traffic efficiency. It facilitates coordination between vehicles, contributing to features like autonomous driving and collision avoidance, ushering in a new era of intelligent transportation.

44

What is network latency and how does it impact online experiences?

Reference answer

Network latency is the delay in data transfer over a network. It's often measured in milliseconds (ms) and represents the time it takes for a packet of data to travel from one point to another. High latency means a longer delay, while low latency means a shorter delay. Latency significantly impacts online experiences. High latency can cause: - Slow loading times for websites - Lag in online games - Buffering in video streaming - Delays in real-time communication (e.g., video calls)

45

If my computer is connected to wireless LAN, can it communicate with computer on wired LAN as well?

Reference answer

- To do this you will need some sort of bridge between the wireless and wired network. This can be accomplished either with a hardware access point or a software access point. Hardware access points are available with various types of network interfaces, such as Ethernet or Token Ring, but typically require extra hardware to be purchased if your networking requirements change. - If networking requirements go beyond just interconnecting a wired network network to a small wireless network, a software access point may be the best solution. - A software access point does not limit the type or number of network interfaces you use. It may also allow considerable flexibility in providing access to different network types, such as different types of Ethernet, Wireless and Token Ring networks. Such connections are only limited by the number of slots or interfaces in the computer used for this task. - Further to this the software access point may include significant additional features such as shared Internet access, web caching or content filtering, providing significant benefits to users and administrators.

46

What is information exemplification?

Reference answer

Information exemplification is the way toward separating data into more modest, sensible lumps before it is communicated across the network. In this cycle that the source and objective delivers are appended to the headers, alongside equality checks.

47

Differentiate between Ad-Hoc and Infrastructure topology and also explain with their advantages and disadvantages?

Reference answer

Wireless networks typically work in one of two configurations: Ad-Hoc or Infrastructure. 1) Ad-Hoc is Latin meaning “for this purpose” so these are the networks which are basically created for some purpose. So these are the group of workstations which communicate directly witch each other to exchange information. An Ad-Hoc network is also called as a peer to peer network. Here are some benefits of an Ad-Hoc network are:- a) The possibilities with Ad-Hoc network are quite endless. b) Ad-Hoc networks are simple to set up. c) Ad-Hoc networks are inexpensive. d) Ad-Hoc networks are fast. Disadvantages of an Ad-Hoc network are as follows:- a) It is not able to get into the mainstream wired local area network. b) It needs more technology to support their reliability. c) As the network increases its speed slows down considerably. 2) In Infrastructure mode, network includes an access point when the wireless clients connect to an access point, which in turn bridges to a network. Infrastructure network can pass information through a central information hub which can be both, hardware or software device on a computer. So under this devices in a wireless network are set up to communicate through an access point. An infrastructure network enables you to:- a) In this you do not have to control over the path your data takes. b) Connect to a wired network. c) Extend your wireless network's range. d) Utilize roaming ability. Disadvantages for Infrastructure network are:- 1. Use of more wireless access points. 2. This increase the cost of implementing a wireless network solution.

48

What is a Session Fixation Vulnerability?

Reference answer

Session fixation occurs when attackers set a fixed session ID. Prevention includes generating random session IDs and updating them after login.

49

Which layer of the OSI model is primarily responsible for flow control?

Reference answer

Transport Layer (Layer 4)

50

What is the difference between a managed and unmanaged switch in a wireless network?

Reference answer

A managed switch provides advanced features like VLANs, QoS, and network monitoring, allowing for greater control and configuration. An unmanaged switch offers basic connectivity without configuration options, suitable for simpler network setups.

51

How can you enhance your home Wi-Fi security?

Reference answer

To enhance your home Wi-Fi security, start by changing the default router password to a strong, unique one. Enable WPA3 encryption (if your router supports it) or WPA2 with AES. Create a guest network for visitors, preventing them from accessing your main network and sensitive devices. Keep your router's firmware updated to patch security vulnerabilities. Additionally, consider disabling WPS (Wi-Fi Protected Setup) due to its known vulnerabilities. Enable the router's firewall and MAC address filtering (though this can be bypassed by sophisticated users), only allowing known devices to connect. Reduce the broadcast range and rename your SSID to something less obvious. For maximum security, consider using a VPN on your devices.

52

What is the difference between IDS and IPS?

Reference answer

Intrusion Detection Systems (IDS) and Intrusion Prevention Systems (IPS) monitor network traffic for suspicious activity. IDS identifies and alerts administrators to potential threats, while IPS takes immediate action to block or mitigate these threats.

53

Explain the concept of channel bonding in wireless networks.

Reference answer

Channel bonding combines two or more adjacent channels to increase the bandwidth available for wireless communication. This technique improves data transfer rates by utilizing additional spectrum, but it may also increase interference with other networks.

54

Can you discuss a time when you had to make a critical network decision under tight deadlines?

Reference answer

Assessment: Gauge the candidate's ability to make sound decisions quickly, considering factors such as network stability, security, and business impact. Red flags: The inability to provide a relevant example or demonstrate indecisiveness in critical situations may indicate a lack of confidence or leadership skills.

55

Which of the multiplexing techniques is used to combine digital signals?

Reference answer

To combine digital signals, time division multiplexing techniques are used.

56

Which multiplexing technique is used in the Fiber-optic links?

Reference answer

The wavelength division multiplexing is commonly used in fiber optic links.

57

What is the difference between synchronous and asynchronous transmission?

Reference answer

Here are some differences between synchronous and asynchronous transmission – | Synchronous transmission | Asynchronous transmission | | Data is sent in blocks or frames | Data is sent in bytes or characters | | Requires synchronization between sender and receiver | Does not require synchronization between the sender and receiver | | Fast and efficient for large amounts of data | Slow and economical for small amounts of data | | Uses timing signals to coordinate data transfer | Uses start and stop bits to indicate data boundaries | | Examples: Telephonic conversations, video conferencing, online gaming | Examples: Email, file transfer, online forms |

58

Where is Quality of Service (QoS) typically implemented in a network?

Reference answer

Quality of Service (QoS) is typically implemented at various points throughout a network where congestion might occur or where prioritization of traffic is crucial. Here are a few potential deployment points: Network Routers: Routers direct traffic through the network and can become congested, especially when handling large volumes of traffic. Implementing QoS at the router helps manage the congestion. Network Switches: Similarly to routers, switches are also significant points of data exchange in a network. Configuring QoS on your switches lets you prioritize certain types of traffic. Network Edge: This is where your network connects to other networks, including the Internet. Deploying QoS at the network edge can provide prioritization for your network traffic as it enters or leaves your network. Wireless Access Points: Wireless networks can often become congestion points, especially with multiple devices connected. QoS on a Wireless Access Point can ensure specific traffic, like VoIP or video conferencing, gets prioritized. In essence, QoS is applied wherever there's a need to prioritize some types of network traffic over others, and especially at network choke points where congestion could occur.

59

Can network slices be dynamically altered or generated?

Reference answer

Yes, network slices can be dynamically altered or generated to adapt to varying demands. This dynamic nature allows operators to allocate resources based on real-time needs, ensuring efficient use of network resources and the ability to support evolving applications and services.

60

What is Cloud Networking?

Reference answer

Cloud networking leverages cloud-based infrastructure for scalability, monitoring, and automation — e.g., AWS VPCs, Azure VNets, or Cisco Meraki.

61

What is a private IP address?

Reference answer

Here's our recommended way to respond to this type of network engineer question that an interviewer may ask you to further understand your technical expertise. "Private IP addresses are designated for use within intranets and serve as non-routable internal network addresses on external public networks. The purpose of private IP addresses is to prevent conflicts within internal networks, ensuring smooth communication and operation. Additionally, the same range of private IP addresses can be reused for multiple intranets, as they remain isolated, enabling efficient and secure utilisation across various internal network environments."

62

What is DHCP (Dynamic Host Configuration Protocol)?

Reference answer

DHCP automatically assigns IP addresses to devices on a network. It simplifies network configuration by eliminating the need for manual address assignment.

63

Which of the following is the primary function of Network Address Translation (NAT)?

Reference answer

To conserve public IP addresses

64

What is a wireless intrusion prevention system (WIPS)?

Reference answer

A WIPS is a system that actively blocks suspicious network traffic to prevent security breaches.

65

Describe a time you resolved a critical network outage under pressure.

Reference answer

In my previous role, we experienced a sudden outage affecting a critical e-commerce application during peak shopping hours. The initial reports pointed to a network connectivity problem, but the scope and root cause were unclear. Under immense pressure to restore service quickly, I began by isolating the affected components. Using network monitoring tools and ping commands, I traced the issue to a misconfigured firewall rule that was inadvertently blocking traffic to the application servers. The firewall rules had been updated recently for a penetration test. After identifying the faulty rule, I immediately adjusted the firewall configuration following our change management process. I documented the changes and communicated the resolution to the stakeholders. I also collaborated with the security team to ensure the restored rule didn't introduce vulnerabilities. Finally, we conducted a post-incident review to prevent similar issues by improving our configuration change management and penetration testing rollback processes.

66

What subnet mask would provide for a network with 50 hosts, while maximizing the number of available subnets?

Reference answer

255.255.255.192

67

What is the primary purpose of TCP window scaling?

Reference answer

To improve performance over high-latency networks

68

What is a USB wireless adapter?

Reference answer

A USB wireless adapter is an external device that plugs into a computer's USB port, providing wireless network connectivity. It is a portable option for devices that do not have built-in wireless capabilities.

69

What is the maximum data rate specified for IEEE 802.11b WLANs?

Reference answer

The maximum data rate for IEEE 802.11b WLANs is up to 11 Mbit.

70

Which of the following best describes the structure and addressing types of IPv6?

Reference answer

128-bit addresses, represented in hexadecimal

71

What is the difference between a 3G, 4G, and 5G network?

Reference answer

3G, 4G, and 5G represent different generations of cellular technology, each offering faster data speeds and improved capabilities. 5G is the latest and offers the highest speeds and lowest latency.

72

Define spectrum management concerning 5G.

Reference answer

Spectrum management in 5G involves the efficient allocation, assignment, and utilisation of radio frequencies. It ensures that each service or application receives the appropriate spectrum resources, minimising interference and maximising the overall performance of the Network.

73

What are the Differences Between TCP and UDP?

Reference answer

TCP is connection-oriented, reliable, and stream-based, while UDP is connectionless and provides best-effort delivery without reliability guarantees.

74

What factors do you consider when designing a data center network?

Reference answer

When designing a data center network, skilled network engineers would focus on factors like scalability, redundancy, and security, to ensure the network can handle increasing data loads and expand as needed. They'd also implement redundant paths and devices to maintain availability and reliability and consider implementing strong security measures, including firewalls, intrusion detection systems, and secure access controls.

75

Outline the roles of MIB and SIB in the 5G framework.

Reference answer

Master Information Block (MIB) and System Information Block (SIB) play pivotal roles in 5G networks. MIB broadcasts fundamental information like cell identity and bandwidth, facilitating device synchronisation. SIBs, on the other hand, convey more detailed and dynamic information, allowing devices to optimise their connection parameters and efficiently utilise the network resources.

76

Define subnet mask

Reference answer

A subnet mask is a number that specifies the range of IP addresses that are available in a network. A subnet mask puts a limit on the number of valid IP addresses. This is the 32-bit number that is used for masking the IP address. Subnet mask divides the IP address into a host address and network address. Two or more systems within the same subnet can communicate with each other. If a system is connected to a network, its subnet mask can be determined by accessing the Network Control Panel.

77

What is ARP and how does it work?

Reference answer

ARP (short for Address Resolution Protocol) maps a device's IP address to its MAC address within a local network. When a device wants to communicate with another, ARP translates the IP address into the corresponding MAC address, ensuring proper data packet delivery within the network.

78

What is Bandwidth?

Reference answer

Bandwidth is a measurement that indicates the highest possible data transmission capacity of a wireless or wired communication channel within a network connection during a specific time frame. Higher bandwidth means more data can be sent and received faster and with fewer errors.

79

What is Confidentiality, Integrity and Availability?

Reference answer

Confidentiality, Integrity, and Availability (CIA) are fundamental concepts in Information Security that ensure the protection, integrity, and accessibility of organisational data assets. a) Confidentiality: Protects sensitive information by limiting access through access controls, encryption, and data categorisation. b) Integrity: Ensures data accuracy and reliability by preventing unauthorised changes. Measures such as Cryptographic hashing and digital signatures ensure validity and identify manipulation. c) Availability: Ensures authorised users can access resources by maintaining resilient infrastructure, redundancy, and disaster recovery strategies.

80

What are Wireless Network Security Measures in an Internal Network?

Reference answer

These include encrypting wireless communication, hiding SSIDs, restricting access devices, and using identity authentication.

81

What is Fast Roaming?

Reference answer

Fast Roaming: Device handshakes with a new AP before roaming to ensure seamless transition and avoid re-authentication.

82

Differentiate between 5G NR and 4G (LTE).

Reference answer

Comparing 5G NR with its predecessor, LTE (4G), provides insights into the advancements made in the new generation. 5G NR surpasses LTE in terms of speed, latency, and connectivity. With higher data rates, lower latency, and support for a huge number of connected devices, 5G NR redefines the possibilities of wireless communication, unlocking new opportunities across industries.

83

How do you answer 'how do you handle stress' interview questions?

Reference answer

How do you handle stress interview answers that actually sound like you? Use these persona-based scripts for students, career switchers, returning applicants.

84

What is Network Topology?

Reference answer

Network Topology refers to the layout of a computer network. It shows how devices and cables are spread out, as well as how they connect.

85

What is a firewall and how does it protect a network?

Reference answer

A firewall acts as a barrier between a trusted internal network and untrusted external networks, such as the internet. Its primary purpose is to control network traffic and prevent unauthorized access to or from the network. It does this by examining network traffic against a set of predefined rules. Firewalls protect a network through various mechanisms, including: - Packet filtering: Inspecting packet headers and allowing or blocking based on source/destination IP, port, and protocol. - Stateful inspection: Tracking the state of active connections and making decisions based on the context of the traffic. - Application-layer filtering: Inspecting the content of traffic at the application layer to block specific applications or threats. - Proxy services: Acting as an intermediary for requests from clients seeking resources from other servers.

86

What normal programming issues can prompt network surrenders?

Reference answer

Programming related issues can be any or a mix of the accompanying:

87

What is your preferred area of expertise within network engineering?

Reference answer

As mentioned, throughout the interview, you should keep referring back to the specific network engineering job youâ€™re interviewing for. However, many employers will want you to have either some experience or awareness of all aspects of network engineering. So, when answering this question, mention all the areas of network engineering you have knowledge and experience in and your preferred area you specialise in. If youâ€™re looking for network engineer interview preparation for these questions, hereâ€™s how you could respond: â€œWhile I find every aspect of being a network engineer enjoyable, there is one particular area where my passion and expertise truly shine when I interact with clients and support with troubleshooting their server issues. I love the challenge of dealing with server and configuration problems and coming up with solutions that allow the client to get the most out of the network theyâ€™re using.â€

88

What commands would you use to troubleshoot a network connectivity issue?

Reference answer

Common troubleshooting commands include: 'ping' to test basic connectivity, 'traceroute' or 'tracert' to identify the path and latency, 'ipconfig' or 'ifconfig' to check IP configuration, 'netstat' to view active connections, 'nslookup' or 'dig' for DNS resolution, 'show interfaces' on network devices to check interface status and errors (including runts and giants), and 'show running-config' to verify device configuration.

89

What causes network congestion?

Reference answer

Network congestion occurs when the demand for bandwidth exceeds the available capacity. Several factors can contribute. Excessive traffic from users or applications can overwhelm network links. Insufficient bandwidth on critical links creates bottlenecks. Faulty network devices, like malfunctioning switches or routers, can cause performance degradation. Misconfigured Quality of Service (QoS) can lead to unfair bandwidth allocation. Broadcast storms, where excessive broadcast traffic floods the network, can cripple performance. Finally, application bottlenecks, where a server or application can't keep up with requests, can also manifest as network congestion.

90

Name two technologies by which you would connect two offices in remote locations.

Reference answer

Two technologies that would connect two offices in remote locations are VPN and Cloud computing.

91

What is QoS (Quality of Service)?

Reference answer

QoS manages bandwidth by prioritizing critical traffic like voice or video. Techniques: - Classification & Marking - Policing & Shaping - Queuing & Scheduling

92

Is there any way to recover my password for WLC?

Reference answer

Password Recovery: Use the CLI and Restore-Password command for versions 5.1 and later; otherwise, reset to factory defaults.

93

What is Security Patch Management?

Reference answer

Security Patch Management involves regularly updating software and systems to fix known vulnerabilities. Keeping patches current helps close security gaps, reducing the risk of exploitation and maintaining robust defenses against emerging threats.

94

What do you mean by a node?

Reference answer

A node is a point where two or more devices connect within a network. A node is where data is received, stored, sent and created within the network. Nodes can be an endpoint for transmitting data or a redistribution point. Any device connected to another device inside a network is a node itself. Common examples of nodes are switches, routers, bridges, and servers, which may be connected or other devices through the internet.

95

What is MPLS?

Reference answer

Multiprotocol Label Switching (MPLS) assigns short labels to packets for faster forwarding rather than IP lookups. It supports QoS, VPNs, and traffic engineering.

96

What is a Site Survey and why is it important?

Reference answer

A Site Survey involves assessing a location to determine the ideal placement of wireless access points for optimal coverage and performance. It helps identify potential sources of interference and ensures adequate coverage throughout the area.

97

What are port numbers, and what are some well-known ports?

Reference answer

A port number is a logical number used by computers to identify all the services or applications running on a device. A Computer can perform many services at the same time, like: - Web browsing - File transfer - Video calls, etc. Now, the computer needs a way to understand which data belongs to which application. That is where the port number is used. Think of a computer like a big apartment building. - The IP Address is the building address. - The port number is the apartment number. The IP Address helps the data reach the correct computer, and the port number helps the data reach the correct application inside the computer. Port number ranges from 0 to 65535. Well-known ports are standard ports that are used by common network services. These numbers are fixed so that devices know which service they should connect to. Some well-known ports are: | Port Number | Protocol/Service | Purpose | | 20/21 | FTP | File transfer | | 22 | SSH | Secure remote login | | 23 | Telnet | Remote login (not secure) | | 25 | SMTP | Sending emails | | 53 | DNS | Domain name to IP conversion | | 67/68 | DHCP | Automatic IP address assignment | | 80 | HTTP | Normal web browsing | | 110 | POP3 | Receiving emails | | 143 | IMAP | Email access | | 443 | HTTPS | Secure web browsing |

98

What are the different types of wireless networks?

Reference answer

Common types of wireless networks include: - WLAN (Wireless Local Area Network): Used for short-range connections within a building or small area. - WAN (Wireless Wide Area Network): Covers larger geographical areas and connects networks across distant locations. - WPAN (Wireless Personal Area Network): Connects devices within a short range, typically for personal use, such as Bluetooth or NFC. - WWAN (Wireless Wide Area Network): Similar to WAN but uses cellular technology for long-range wireless connections.

99

Define IP Address and Its Types.

Reference answer

An IP (Internet Protocol) address is a unique identifier assigned to each device on a network. There are two types of IP Addresses: - IPv4: IPv4 addresses are 32-bit addresses written in dotted decimal format. It approximately allows 4.3 billion unique addresses. Example: 192.168.1.1 - IPv6: IPv6 addresses are 128 bits and are represented in hexadecimal format. It enables a vast number of unique addresses to meet future demands. Example: 2001:0db8:85a3:0000:0000:8a2e:0370:7334

100

What is a Link?

Reference answer

A connection alludes to the availability of two gadgets. It incorporates the kind of links and conventions utilized for one gadget to have the option to speak with the other.

101

What are the challenges of securing cloud-based networks?

Reference answer

Securing cloud-based networks involves addressing data privacy concerns, managing shared responsibilities, and ensuring secure authentication and authorization. A comprehensive strategy is needed to maintain data confidentiality, integrity, and availability.

102

Describe the concept of power over Ethernet (PoE) and its benefits.

Reference answer

Power over Ethernet (PoE) allows network cables to carry both data and electrical power to devices such as access points and IP cameras. It simplifies installation by reducing the need for separate power sources and outlets.

103

What is the difference between a vulnerability assessment and a penetration test?

Reference answer

A vulnerability assessment is a process of identifying and evaluating security vulnerabilities in a network or system. It provides a broad view of potential weaknesses but does not typically involve exploiting these vulnerabilities. A penetration test, on the other hand, involves simulating real-world attacks to actively exploit vulnerabilities and assess the effectiveness of security controls. Penetration testing provides a more in-depth evaluation by demonstrating how an attacker might exploit weaknesses to gain unauthorized access.

104

Cisco 5520 Wireless Controller supports how many clients and APs?

Reference answer

Supports Up to 1500 Access Points.

105

What is MPLS, and how does it improve network traffic flow?

Reference answer

MPLS, or Multiprotocol Label Switching, is a method for directing traffic on a network. It uses labels to forward data instead of long network addresses. This makes the process simpler and faster. Once data enters an MPLS network, it gets a label. Then the data is sent rapidly by network devices using this shorter label along an already established path. This eliminates the need for complicated routing choices at each step. Through this, a more efficient and reliable network is achieved, which can be helpful to businesses that require high-quality connections to run their applications. MPLS improves traffic flow in several ways: - It uses labels for faster forwarding decisions. - It creates predictable paths for data to follow. - It reduces the work routers have to do. - It allows for prioritizing important traffic. - It helps manage network congestion better.

106

What is link aggregation and what are its benefits?

Reference answer

Link aggregation, also known as Ethernet bonding or port trunking, is a method of combining (aggregating) multiple network connections in parallel. The aim is to increase throughput beyond what a single connection could sustain and to provide redundancy in case one of the links fails. By aggregating several network connections into a single virtual link, link aggregation allows for more data to be transferred at the same time, effectively increasing the available bandwidth. Moreover, it improves network reliability because if one link in the aggregate fails, the other links remain active, providing uninterrupted service. For businesses with high network demands or those seeking greater network redundancy and load balancing, link aggregation is an efficient and cost-effective strategy. It enables the optimization of data transfer rates, and at the same time, improves the reliability and availability of network connections. However, it's important to remember that for link aggregation to work, the switch or router on the other end of the connections needs to support link aggregation as well. Most enterprise-grade network hardware supports it, but it might not be available on home or small office equipment.

107

How can wireless networks be protected?

Reference answer

Wireless protection is key to safeguarding confidential data. Passwords need to be strong (WPA2 and WPA3 encryption). Disabling SSID broadcasting reduces the network to hardcore scanners. MAC address filtering keeps other devices from connecting to your network. Implementing a firewall is the second level of defence. Instead, Keep patching the firmware regularly to get rid of security holes. Putting guest networks separate from the main network removes clueless access. And we should never underestimate the importance of a security audit, in order for penetration testers help us identify any holes.

108

What is a trunk port?

Reference answer

A trunk port is a network link that carries data for many VLANs over a single connection. Its main job is to connect switches, allowing VLANs to stretch across multiple devices. Trunk ports handle traffic from many different VLANs. Trunk ports add a special tag to each piece of data. This tag identifies which VLAN the data belongs to. The receiving switch reads the tag to send the data to the correct destination. This system makes the network more efficient and flexible.

109

How would you go about troubleshooting an issue with a network?

Reference answer

Troubleshooting issues is a common responsibility of network engineer jobs. Therefore, it shouldn't come as a surprise to you when we say this question should become a key part of your network engineer interview preparation. Here, the interviewer will expect you to talk them through how you would typically troubleshoot a networking problem. We've created another example response for how you can answer this question effectively: "When tasked with troubleshooting a network issue, I follow a systematic approach that begins with identifying the problem at hand and formulating a working hypothesis as to why the problem has occurred. I'll then validate my theory by executing relevant procedures or implementing specific codes. Throughout the troubleshooting process, I carefully look into the outcomes and make necessary adjustments until I successfully pinpoint both the root of the problem and the appropriate solution. This methodical approach allows me to tackle network challenges effectively and efficiently with minimal downtime for the end user."

110

What is a wireless sensor network (WSN)?

Reference answer

A WSN is a network of wireless sensor nodes, typically used for data collection and monitoring in applications like environmental monitoring, industrial automation, and healthcare.

111

What is a wireless intrusion detection system (WIDS)?

Reference answer

A WIDS is a system that monitors network traffic for suspicious activity and alerts administrators to potential security threats.

112

What is Network Security Situational Awareness?

Reference answer

Network security situational awareness involves comprehensively perceiving and understanding the security status of a network. It includes real-time monitoring, predicting potential risks, and supporting decision-making.

113

Discuss the working principles of MPLS (Multiprotocol Label Switching) and its applications in networks.

Reference answer

MPLS is a technology that enables efficient data transfer in IP networks by tagging data packets to simplify routing decisions. It supports applications such as Virtual Private Networks (VPNs), traffic engineering, and Quality of Service (QoS) management.

114

What is a router and how does it work?

Reference answer

A router is a hardware device that essentially works as a post office for your network, directing the flow of data packets between devices. It works by connecting networks and directing packets, based on IP addresses, to their destination over the most expedient route possible. When the router receives a data packet, it reads the packet's destination IP address, then it consults its routing table, which is a database of known networks and how to reach them. Using this information, it then routes the packet accordingly, be it to an internal device in your home network or to another network over the internet. In a home network, a router often serves two main functions. It connects your network of personal devices, like your PC and smart TV, to each other in a local area network (LAN), and it also connects your LAN to the wide area network (WAN), usually the internet. So, if you're streaming Netflix on your smart TV, the data comes from Netflix's servers over the internet, enters your home via your router, and the router then directs it to your TV.

115

What is a VLAN (Virtual LAN)? Why is it used?

Reference answer

A VLAN is a way to divide a single physical network into multiple logical networks using a switch. Even though all devices may be connected to the same switch, VLANs make it work as if there were separate networks. Okay, so to understand this better, you should think of LAN. In a regular setup, all devices connected to a switch belong to the same broadcast domain. So any broadcast message like ARP is sent to everyone. Now here's what VLAN does. - Basically all the devices are grouped into different VLANs, and each VLAN acts like its own separate network. So from here, broadcast traffic stays within that VLAN and does not reach others. - Another interesting part is that devices in the same VLAN can communicate as if they are on the same LAN, even if they are connected through different physical switches. This is possible because VLAN information is carried across all the switches by using the 802.1Q standard, which adds a VLAN ID ranging from 1 to 4094 to Ethernet frames. Now, what if two devices are in different VLANs? Unfortunately, they won't be able to communicate directly. Communication between VLANs requires inter-VLAN routing, which is done using either a router or a Layer 3 switch. So Why VLANs are actually used? With the use of VLAN, the grouping becomes possible based on function instead of physical location. For example: There can be HR department in one VLAN and Engineering in another This mainly helps in: - improving security - reducing broadcast traffic - making network management more flexible Because of this, most switches use VLAN 1, unless it is configured to be otherwise.

116

What kind of error is undetectable by the checksum?

Reference answer

In checksum, multiple-bit errors can not be undetectable.

117

What is the Software Layer or User Support Layer in the OSI model?

Reference answer

The OSI model's software layers, often known as user support layers, are the Presentation Layer (Layer 6) and the Application Layer (Layer 7). The Presentation Layer conducts data translation, encryption, and compression to ensure system compatibility. The Application Layer delivers network services directly to end users and apps, allowing them to do operations like email, web browsing, and file transfer.

118

What is a wireless network analyzer?

Reference answer

A wireless network analyzer is a tool that scans for nearby wireless networks and provides information about their signal strength, channel usage, and security settings. It helps identify interference sources and optimize network performance.

119

Discuss the applications and advantages of virtualization technology in networking.

Reference answer

Virtualization abstracts physical network resources (e.g., servers, storage, network devices) into logical ones, enabling dynamic resource allocation and optimization. It supports applications such as Virtual Network Functions (VNF), Virtual Private Networks (VPNs), and Network Function Virtualization (NFV), enhancing flexibility, scalability, and security.

120

Why do we OSPF a protocol that is faster than our RIP?

Reference answer

OSPF stands for Open Shortest Path First which uses a link-state routing algorithm. This protocol is faster than RIP because: - Using the link-state information which is available in routers, it constructs the topology of Bluetooth which Bluetooth the topology determines the routing table for routing decisions. - It supports both variable-length subnet masking and classless inter-domain routing addressing models. - Since it uses Dijkstra's algorithm, it computes the shortest path tree for each route. - OSPF (Open Shortest Path First) is handling the error detection by itself and it uses multicast addressing for routing in a broadcast domain

121

What are rights in networking?

Reference answer

Rights refer to the authorized permission to perform specific actions on the network. Each user on the network can be granted individual rights, depending on what needs to be considered by that user.

122

How would team members in the past describe you?

Reference answer

This question provides insight into the candidate's teamwork and interpersonal skills based on past feedback.

123

How do you optimize wireless network performance in high-density environments?

Reference answer

Managers ask this to gauge your hands-on experience optimizing WLANs in challenging scenarios. They want to see that you can apply a multi-faceted approach. Successful candidates for a wireless network engineer job outline these essential strategies: Channel allocation and power management Client load balancing across access points Band steering implementation QoS policy configuration Interference mitigation techniques

124

What is IPv6? How is it different from IPv4?

Reference answer

Internet Protocol Version 6, or popularly called IPv6 is an updated version of IP addressing, and (might sound silly), but the main reason for its launch was because IPv4 ran out of addresses. IPv4 used 32-bit addresses, which gave roughly 4.3 billion unique combinations. And at that time, it sounded like a lot, but with phones, laptops, IoT devices, etc., it ended up not being enough. Hence, IPv6 was introduced to solve this by using 128-bit addresses which were written in hexadecimal format: 2001:0db8:85a3::8a2e:0370:7334 With this format, an almost unlimited space was created, so every device could have its own unique IP. Also, this is why IPv doesn't rely on NAT the way IPv did. We spoke about spaces, but there's more to their differences! 1. IPv6 makes the packet header simpler than IPv4 did to make routing efficient. 2. Reducing unnecessary traffic became important, and that is IPv6 replaced broadcasting traffic with multicast communication. 3. You must also note that another important thing about IPv6 is that it has built-in IPSec support. It's useful because this makes it easier to have communication at the protocol level with IPv6. 4. You will also notice that IPv6 supports something called auto-configuration, which is also known as SLAAC. This means that devices can create their IP addresses without needing a DHCP server in many cases, with IPv6. So, where do they both stand currently? Basically, IPv6 hasn't fully replaced IPv4; instead, they are working together as a dual-stack setup. One thing you must not forget here is that both systems don't communicate directly. They require transition mechanisms like dual-stack, tunneling, or NAT64 to work together.

125

What is a Wi-Fi Hotspot?

Reference answer

Wi-Fi Hotspot: Physical location providing Internet access via a wireless local area network using a router connected to an ISP.

126

How Flow Control is Achieved in TCP?

Reference answer

In computer networks, reliable data delivery is important. The Transmission Control Protocol guarantees in-order and error-free data transfer using flow control. This is to prevent the sender from flooding the receiver so as to make sure it can work efficiently in turn. TCP utilizes a sliding window protocol for flow control. The receiver advertises a window size, indicating the number of bytes its buffer can hold. The sender transmits data segments up to this advertised window

127

What is the role of a wireless controller in a network?

Reference answer

A wireless controller manages and configures multiple wireless access points from a central location. It provides centralized management, monitoring, and optimization of wireless networks, including features like roaming, load balancing, and security.

128

Describe the process in detail on how wifi client gets on the wifi network and starts passing traffic

Reference answer

Pretty much the same answer as question 1.

129

What are the authentication protocols 802.1x and EAP, and what is their role in network security?

Reference answer

The content explains the authentication protocols 802.1x and EAP, and their role in network security, but does not provide specific details in the given text.

130

What is DHCP and how does it function?

Reference answer

DHCP (Dynamic Host Configuration Protocol) is a protocol that automatically assigns IP addresses to network devices. When a device joins the network, the DHCP server assigns it an IP address, gateway, and other network parameters, simplifying network management.

131

Two PCs are in the same VLAN but cannot communicate. What could be the issue?

Reference answer

Here is a list of possible reasons: - Incorrect subnet mask - The host firewall is blocking traffic - Duplicate IP addresses - Switch port security restrictions - One port accidentally assigned to another VLAN - NIC issues Here's how you can solve it: - First, you should verify IP configurations - Then, check VLAN membership - Ping both devices - Check the ARP table - Inspect switch configuration

132

What is Wi-Fi technology and how does it work?

Reference answer

Wi-Fi uses radio waves to provide wireless network connectivity between devices within hotspots near wireless routers.

133

What are the common types of wireless network topologies?

Reference answer

Common wireless network topologies include: - - Infrastructure: Devices connect to a central access point or wireless controller. - Ad-Hoc: Devices communicate directly with each other without an access point. - Mesh: Devices form a network by connecting to multiple access points, creating a self-healing network.

134

What is a LAN?

Reference answer

A LAN stands for Local Area Network. It refers to the connection among computers and other network devices located within a small physical area.

135

What is the ARP Protocol?

Reference answer

ARP (Address Resolution Protocol) resolves a 32-bit IP address into a MAC address, enabling communication in a network.

136

What is the fundamental motivation behind OSPF?

Reference answer

OSPF, or Open Shortest Path First, is a connection state directing convention that utilizations steering tables to decide the ideal way for information trade.

137

How would you assess a client's needs when optimising a network?

Reference answer

Your potential employer will consider its clients one of the business's most important assets. Therefore, they'll want to know you have their client's needs at the forefront of everything you do. When answering these types of network engineer interview questions, the interviewer wants you to explain how you would collate and analyse the client's requirements concerning their network. As part of your network engineer interview preparation, hereâ€™s how you can answer this question: â€œWhen tasked with creating or enhancing a customer's network, I adopt an inquisitive approach. During the initial stages, I invest time in asking a multitude of questions to gain a comprehensive understanding of the clientâ€™s needs and expectations. Once Iâ€™ve gathered and clarified all this information, Iâ€™ll then proceed to formulate a solution that aligns with their specific needs. Iâ€™ll use this process to ensure that the end result meets or exceeds the clientâ€™s expectations and provides the best possible network solution tailored to their specific goals.â€

138

What are the Differences Between TCP and UDP?

Reference answer

TCP (Transmission Control Protocol) is a connection-oriented, reliable, byte-stream-based transport layer protocol. In contrast, UDP (User Datagram Protocol) is connectionless, focuses on best-effort delivery, and does not guarantee reliability.

139

What is Quality of Service (QoS) and how can it be implemented?

Reference answer

Quality of Service (QoS) refers to the ability of a network to provide differentiated service to specific network traffic. The goal of QoS is to improve the user experience by prioritizing critical traffic and minimizing latency, jitter, and packet loss for delay-sensitive applications like VoIP and video conferencing. QoS can be implemented through various mechanisms to prioritize network traffic. Some common techniques include: - Classification: Identifying and marking traffic based on application, source/destination IP, or port. - Queuing: Using different queues (e.g., Priority Queuing, Weighted Fair Queuing) to prioritize traffic. - Traffic Shaping: Controlling the rate of traffic to prevent congestion. - DSCP Marking: Using the Differentiated Services Code Point field in the IP header to signal QoS requirements.

140

What is VLAN, and What is Its Purpose?

Reference answer

A VLAN (Virtual Local Area Network) is a logical grouping of devices that can communicate as if they are on the same physical network, even if they are on different physical segments. VLANs enhance network flexibility and control broadcast storms.

141

What is an IP address?

Reference answer

Imagine your house needs an address so the mailman knows where to deliver your letters. An IP address is like that, but for computers on the internet. It's a unique number that identifies your device (like your phone or laptop) so that information can be sent to the correct place. Think of it this way: if you want to visit a website, your computer asks the website's server for the content. Your computer needs to tell the server its IP address so the server knows where to send the website data back to. There are two main types, IPv4 and IPv6. IPv4 addresses look like this: 192.168.1.1 . IPv6 addresses are longer and use hexadecimal numbers.

142

How would you design a highly available network architecture?

Reference answer

Designing a highly available network architecture involves redundancy, fault recovery, and load balancing. This can include deploying active-active or active-passive data center setups, using redundant devices and links, and implementing automated fault detection and recovery mechanisms.

143

How would you translate technical ideas to non-technical people?

Reference answer

Network engineer jobs often require candidates to have the ability to communicate ideas, processes, and protocols to the wider business, from other tech-savvy employees to non-technical minds, in a way that is translated and understood across the board. Interviewers often look for candidates that possess the ability to tailor their approach to different audiences with an ability to simplify complex tech jargon. Knowing how to prepare for network engineer interview questions like this is simple, especially after reading our example response. "I always strive to adapt my communication style to match the knowledge level of the person I'm speaking with, whether it's a colleague or a client. I do my best to employ simple terms and easy-to-understand language when conversing with individuals outside the networking domain. I often use analogies when translating complicated topics to people, as I find this approach makes things simpler for others to grasp intricate ideas."

144

What is the change in WLAN-11ac with respect to previous versions of WLAN?

Reference answer

WLAN-11ac has been introduced after previous versions of WLAN, which include 802.11a, 11b, 11g, and 11n. An 80MHz channel bandwidth is added. The number of MIMO streams has been enhanced to eight. 256QAM has been added.

145

What enhancements does IPv6 provide and how are mixed environments supported?

Reference answer

Next to the address space, IPv6 provides enhancements like a reduced header format for faster processing, autoconfiguration (simplified device initial setup), and more optimization for mobile environments. To support mixed environments where both protocols are in use, an IPv6 to IPv4 converter is often required to enable communication and address translation between IPv6 and legacy IPv4 networks.

146

What experience do you have with network monitoring tools?

Reference answer

I have experience with various network monitoring tools, including Wireshark for packet analysis, Nagios for monitoring network performance and availability, and SolarWinds for managing network configurations and monitoring traffic.

147

Define HTTPS protocol.

Reference answer

Hypertext Transfer Protocol Secure, or HTTPS, represents an extension of the conventional HTTP protocol tailored for secure data transmission across computer networks, predominantly the Internet. HTTPS emphasises data security by encrypting data exchanged between web browsers and servers, protecting sensitive information. This includes user credentials and financial transactions, thwarting interception by malicious entities. HTTPS establishes a secure communication channel between the client and server using SSL/TLS encryption protocols.

148

What is RIP?

Reference answer

RIP, or Routing Information Protocol, is used by routers to send data from one network to another. It effectively manages routing data by broadcasting its routing table to all other routers within the network.

149

What is WPA3 and how does it improve Wi-Fi security?

Reference answer

WPA3 (Wi-Fi Protected Access 3) is the latest wireless security protocol that helps improve Wi-Fi security. It provides stronger encryption, protecting data transmitted over the network. WPA3 includes features like Simultaneous Authentication of Equals (SAE) for more secure password-based authentication and forward secrecy, ensuring that past sessions remain secure even if a password is compromised.

150

What is NAT and why is it used?

Reference answer

NAT (Network Address Translation) modifies IP addresses in packet headers while they transit through a router. It allows multiple devices on a local network to share a single public IP address for accessing the internet. It enhances security by masking internal IP addresses and conserves the number of public IP addresses needed.

151

Enumerate the key advantages of implementing network slicing in 5G.

Reference answer

Network slicing offers enhanced flexibility, resource optimisation, and tailored service delivery. It enables operators to efficiently allocate resources based on specific requirements, ensuring optimal performance for each slice and accommodating a diverse range of 5G Applications with distinct needs.

152

What is the difference between a VLAN and a subnet?

Reference answer

A VLAN (Virtual Local Area Network) is a logical segmentation of a network at Layer 2 (data link layer), allowing devices to be grouped together regardless of physical location. A subnet is a logical subdivision of an IP network at Layer 3 (network layer), used to organize IP addresses and control broadcast domains. VLANs are often mapped to subnets, but they operate at different OSI layers: VLANs separate traffic at Layer 2, while subnets separate traffic at Layer 3.

153

What is the OSI model and why is it useful?

Reference answer

The OSI (Open Systems Interconnection) model is a conceptual framework that standardizes the functions of a telecommunication or computing system into seven distinct layers. Each layer has specific responsibilities, ensuring interoperability between different network devices and software. These layers are, from top to bottom: Application, Presentation, Session, Transport, Network, Data Link, and Physical. The OSI model is useful because it provides a common language for network professionals, simplifies network troubleshooting by breaking down complex communication processes into manageable parts, and promotes modularity in network design, allowing for easier updates and development of new technologies. It provides a structured way to understand how data travels from one application to another over a network.

154

What is Anonymous FTP?

Reference answer

Anonymous FTP is a way of granting user access to files on public servers. Users allowed access to data on these servers do not need to identify themselves but instead log in as anonymous guests.

155

How does DNS work, and why is it critical?

Reference answer

DNS (Domain Name System) converts human-readable domain names into machine-readable IP addresses using a hierarchical network of DNS servers. It's crucial for enabling user-friendly access to network resources without remembering numerical IP addresses.

156

What is Netstat?

Reference answer

Netstat is a command-line utility program. It gives valuable data about the current TCP/IP settings of an association.

157

What are the advantages of using a VPN?

Reference answer

Below are few advantages of using VPN: - VPN is used to connect offices in different geographical locations remotely and is cheaper when compared to WAN connections. - VPN is used for secure transactions and confidential data transfer between multiple offices located in different geographical locations. - VPN keeps an organization's information secured against any potential threats or intrusions by using virtualization. - VPN encrypts the internet traffic and disguises the online identity.

158

Explain the difference between TCP and UDP, and when you would use each.

Reference answer

Look for an answer that highlights TCP's reliability and connection-oriented nature versus UDP's speed and connectionless nature. Bonus points if they can provide real-world examples, like TCP for web browsing and UDP for video streaming.

159

What is a reverse proxy?

Reference answer

Reverse Proxy Server: The job of a reverse proxy server is to listen to the request made by the client and redirect to the particular web server which is present on different servers. This is also used to restrict the access of the clients to the confidential data residing on particular servers. For more details please refer to what is proxy server article.

160

Why are VLANs required at the switch level?

Reference answer

VLANs are required at the switch level. There is only one broadcast domain at the switch level. This means whenever a new user is connected to a switch, they become part of the same broadcast domain, so VLANs are needed to separate these domains.

161

Why is redundancy important in networking?

Reference answer

Redundancy is extremely important in networking. Essentially, it's about having backup components or systems in place that can take over if the primary ones fail. It could be anything from having duplicate hardware like switches and routers, additional network paths, or backup servers in case the main ones go down. The main aim of redundancy is to guarantee network availability and minimize the risk of downtime which could result in an interruption of services. For businesses, network downtime could mean significant losses, not just in terms of revenue but also reputation, customer trust, and productivity. Further, redundancy also contributes to load balancing. For instance, in times of high network traffic, redundant components can share the load and help maintain optimal performance. So, while redundancy might require additional expenditures upfront for the extra hardware or software components, the benefits it provides in terms of network reliability, uptime, and performance make it a critical aspect of any robust network design.

162

What is NAT and why is it used?

Reference answer

Network Address Translation, or NAT, is a method used in networking to conserve public IP addresses and increase security. It manipulates IP addresses in the IP packet headers, allowing a single device, such as a router, to act as an agent between the Internet and a local network, which means that only a single unique IP address is required to represent an entire group of computers to anything outside their network. When computers on the local network transmit data to the internet, NAT modifies the source IP in the outgoing packet header to its own public IP address. Conversely, when data arrives from the internet, NAT converts the destination IP back to the relevant private IP address of the local computer. This is crucial because the number of available IPv4 addresses is less than the amount required for every individual device worldwide to have its own unique public IP. NAT mitigates this by allowing many devices with private IPs on a local network to share a single public IP for communicating over the internet. Importantly, it also enhances security because it essentially hides the IP addresses of individual devices on a local network, making them less susceptible to direct attacks.

163

What is OSI, and which job does it play in a PC network?

Reference answer

OSI is called Open Systems Interconnect and fills in as a source of the perspective model for information correspondence. PC network OSI is comprised of 7 layers, with each Layer characterizing a particular part of how network gadget interface and speak with each other network gadgets in the PC network. One Layer may manage the physical media utilized, while another layer directs how information is sent across the network.

164

What is a network protocol?

Reference answer

A network protocol is a set of rules that govern how devices communicate over a network. It defines the format, order, and meaning of messages exchanged between devices. Essentially, it's a standardized way for devices to understand each other. For example, HTTP (Hypertext Transfer Protocol) is a network protocol used for transferring data over the web. When you access a website, your browser sends an HTTP request to the web server, and the server responds with an HTTP response containing the website's content.

165

How many IFSs are there? Where can we use these? Which IFS is the shortest? Which IFS is variable?

Reference answer

♣ There are 6 IFSs are there. RIFS, SIFS, PIFS, DIFS, AIFS, EIFS. ♣ In short => RIFS: 11n, SIFS: Between Data and ACK, PIFS: Urgent frame transmission, AIFS: WMM enabled client, EIFS: For Retransmitted]. ♣ RIFS->2us. ♣ AIFS->Depends on AIFSN. ♠ For detailed explanation : IFS

166

What are 20 interview questions for manager position candidates?

Reference answer

20 interview questions for manager position candidates, with answer patterns for first-time managers, STAR and STARR examples, and the questions that show you.

167

What are the different Wi-Fi generations and also explain any one?

Reference answer

The IEEE 802.11 generation is actually only the earliest standard, allowing 1-2 Mbps of bandwidth. Amendments have be made to the original standard in order to optimize bandwidth (these include the 802.11a, 802.11b and 802.11g standards, which are also called 802.11 physical standards) or to better specify components in order to ensure improved security or compatibility. Name of Generation- 802.11a Name- WiFi5 Description- The 802.11a standard (called Wi-Fi 5) allows higher bandwidth (54 Mbps maximum throughput, 30 Mbps in practice). The 802.11a standard provides 8 radio channels in the 5 GHz frequency band.

168

How does a wireless repeater work, and when would you use one?

Reference answer

A wireless repeater receives and retransmits wireless signals to extend coverage in areas with weak signal strength. It is used to enhance signal coverage in large or obstructed areas, improving connectivity for devices at the network's edge.

169

Which layer of the OSI model is primarily responsible for data encryption and decryption?

Reference answer

Presentation Layer (Layer 6)

170

What is a MAC address?

Reference answer

The Media Access Control (MAC) address holds significant importance in computer networking, similar to that of an IP address. It is also known as a physical, hardware, or burned-in address. It is a 12-digit hexadecimal number divided into six octets. The first three octets indicate the organization that issued the address, and the last three identify the specific device. MAC addresses direct data packets to the correct destination on a local network.

171

What are the key principles for designing a secure network architecture?

Reference answer

Designing a secure network architecture involves several key principles: ● Defense in Depth: Implement multiple layers of security controls to protect against threats at various levels. ● Network Segmentation: Divide the network into segments to limit the spread of potential attacks and control access based on sensitivity. ● Least Privilege: Apply the principle of least privilege to ensure users and systems only have the access necessary for their roles. ● Regular Monitoring and Logging: Continuously monitor network traffic and maintain logs to detect and respond to potential security incidents. ● Risk Assessment: Conduct regular risk assessments to identify and address potential security weaknesses.

172

What is the difference between switching and routing?

Reference answer

In a nutshell, both switching and routing are essential network functions, but they operate at different layers and handle data in different ways. Switching operates at the data link layer (Layer 2) of the OSI model and is chiefly used to handle data transmission within a single network, often referred to as a Local Area Network (LAN). Switches primarily deal with MAC addresses and send data packets to specific devices in the network, using the information on MAC addresses. Routing, on the other hand, operates at the network layer (Layer 3). Routers are typically used to connect multiple networks together, forming an internetwork, often the most common case being connecting a local network to the internet. Routers handle IP addresses and use IP routing tables to decide where to send data packets next, based on their destination IP address. In other words, switches are responsible for directing and forwarding data on a single network, whereas routers primarily handle the task of linking and forwarding data across multiple networks. Both functions are essential for data to move efficiently in and between networks.

173

How do you troubleshoot RF issues?

Reference answer

This question assesses the candidate's ability to diagnose radio frequency problems, such as interference, signal degradation, or channel overlap, using spectrum analyzers and site surveys.

174

What is port forwarding and when might you need to configure it?

Reference answer

Port forwarding allows you to redirect network traffic from one port number on a network device (like a router) to another port number on a different device within the same network, or even to a different port on the same device. It's like having a receptionist at your router who knows where to send incoming calls (network requests). You might need to configure port forwarding to: - Host a game server on your local network - Access a security camera system remotely - Set up a web server or FTP server accessible from the internet - Allow remote desktop connections to a specific computer on your network

175

What does network topology dictate?

Reference answer

Network topology dictates what media you should use to interconnect devices. It also serves as a basis for selecting the materials, connectors, and terminations suitable for the configuration.

176

Which two wireless encryption methods are based on RC4 encryption algorithm?

Reference answer

WEP and WPA (version 1) are based on the RC4 encryption algorithm.

177

What is a Proxy Server?

Reference answer

Proxy Servers act as intermediaries between client devices and the internet, handling requests and responses. They enhance security by providing anonymity, filtering content, and masking users' IP addresses while defending against malicious content.

178

Discuss methods and techniques for network congestion control.

Reference answer

Network congestion control ensures efficient operation during peak traffic periods. Methods include traffic shaping, congestion avoidance algorithms (e.g., TCP's slow start and congestion avoidance), queue management (e.g., FIFO, priority queues), and Content Delivery Networks (CDNs) for traffic distribution.

179

What is the capacity of the OSI Session Layer?

Reference answer

This Layer gives the conventions and intends for two network gadgets on the network to speak with one another by holding a meeting. This incorporates setting up the meeting, overseeing data trade during the meeting, and destroy the endless supply of the meeting.

180

How do you ensure network documentation is accurate and up-to-date?

Reference answer

Assessment: Examine the interviewee's attention to detail, organizational skills, and commitment to maintaining comprehensive network documentation. Red flags: Lack of emphasis on documentation practices or disorganized approaches to network documentation may suggest a lack of accountability or professionalism.

181

What do understand by domain and workgroup?

Reference answer

Domain is a group of computers in a network, which are connected. The members of a domain consist of users, workstations and database servers. Devices within the same domain are administered using the same protocols and rules. When an active directory is installed, a domain is created. Domains can be used for administering computers centrally, which is not possible in a workgroup. A workgroup is a set of connected computers that share resources. Here, all the computers are peers and they do not have control over one another. All peers must be on the same LAN and subnet.

182

Explain the significance of validation.

Reference answer

Validation is the way toward checking a client's accreditations before he can sign into the network. It is typically performed utilizing a username and secret phrase. This gives safe methods for restricting access from undesirable gate-crashes on the network.

183

What EAP method do you prefer and why?

Reference answer

This question assesses the candidate's knowledge of Extensible Authentication Protocol (EAP) methods, such as EAP-TLS or PEAP, and their security and deployment considerations.

184

What is a captive portal?

Reference answer

A captive portal is a web page that users must access before they can connect to a wireless network. It typically requires authentication, such as accepting terms of service or entering login credentials.

185

Can you describe the best way to secure a company's LAN?

Reference answer

Assesses the candidate's knowledge and experience in setting up secure networks.

186

Which of the following is a common type of denial-of-service (DoS) attack that exploits the TCP three-way handshake?

Reference answer

SYN flood

187

How do you configure a wireless access point for optimal performance?

Reference answer

To configure an access point for optimal performance: - - Set appropriate channel and channel width. - Adjust transmit power to balance coverage and interference. - Implement band steering to distribute clients between 2.4 GHz and 5 GHz bands. - Regularly update firmware and monitor network performance.

188

What are your preferred tools for WarDriving?

Reference answer

Preferred tools for WarDriving are as follows:- a) Kismet- Kismet is a 802.11b wireless network sniffer. It is capable of sniffing using almost any wireless card supported in Linux. b) Airsnort- is one of the first tools to come out discovering insecurity of wireless network. AirSnort is a wireless LAN (WLAN) tool which cracks encryption keys on 802.11b WEP networks. AirSnort operates by passively monitoring transmissions, computing the encryption key when enough packets have been gathered. c) WEPCrack is Perl based tool. WEPCrack is a tool that cracks 802.11 WEP encryption keys using the latest discovered weakness of RC4 key scheduling. d) WaveStumbler is console based 802.11 network mapper for Linux. It reports the basic AP stuff like channel, WEP, ESSID, MAC etc. e) Aircrack yet another WEP cracking tool for Linux courtesy by divine.

189

Which of the following accurately describes the three-way handshake process used in TCP to establish a connection?

Reference answer

SYN, SYN-ACK, ACK

190

What are routing protocols and can you give examples?

Reference answer

Routing protocols enable routers to dynamically learn and exchange network topology information, enabling efficient data packet delivery. Examples include: - OSPF (Open Shortest Path First): A link-state routing protocol that calculates the shortest path to each network. - BGP (Border Gateway Protocol): A path-vector protocol used for routing between autonomous systems on the internet. - EIGRP (Enhanced Interior Gateway Routing Protocol): A Cisco-proprietary advanced distance-vector protocol. - RIP (Routing Information Protocol): A distance-vector protocol that uses hop count as its metric.

191

What is a Tunnel mode?

Reference answer

This is a mode of data exchange wherein two communicating computers do not use IPSec themselves. Instead, the gateway that is connecting their LANs to the transit network creates a virtual tunnel that uses the IPSec protocol to secure all communication that passes through it. Tunnel mode is most commonly used between gateways, or at an end-station to a gateway, the gateway acting as a proxy for the hosts behind it. Tunnel mode is most commonly used to encrypt traffic between secure IPSec gateways, such as between the Cisco router and PIX Firewall

192

What is SDN (Software Defined Networking)?

Reference answer

SDN decouples the control plane from the data plane, providing centralized management via a controller (e.g., Cisco APIC, OpenDaylight). Benefits include automation, agility, and programmability.

193

What is a Proxy Server?

Reference answer

A proxy server acts as an intermediary, improving security and caching web content for performance optimization.

194

What is SNMP and how does it work?

Reference answer

SNMP, or Simple Network Management Protocol, is a protocol used in networking for managing and monitoring network devices. Think of it as a communication rulebook for network devices like routers, switches, servers, printers, and even laptops and desktops. SNMP allows network administrators to oversee network performance, find and solve network issues, and occasionally, plan for network growth. It operates by sending protocol data units (PDUs) to different parts of a network, and upon arrival, the PDU is used for monitoring and controlling these network devices. The protocol includes a set of standards for network management, including an application layer protocol, database schema, and a set of data objects. To put it simply, SNMP provides a way to get or set the values of variables in the database schema, which is particularly useful for tracking and controlling network behavior.

195

What is an Intrusion Detection System (IDS)?

Reference answer

IDSs are systems that monitor network or system activities to identify and alert on suspicious behavior or breaches of security policies. They provide real-time alerts, allowing organizations to detect and address potential threats swiftly, thereby improving their security posture.

196

Describe a time when you identified and resolved a network performance bottleneck.

Reference answer

At Cisco, I encountered a significant network slowdown affecting multiple departments. I used Wireshark to analyze traffic patterns and identified a rogue application consuming bandwidth. I collaborated with the IT team to block the application and optimized routing protocols. Post-resolution, we saw a 40% improvement in network performance and received positive feedback from users about the restored service quality.

197

What is a hub?

Reference answer

A hub refers to a point or joint where a connection occurs. It can be a computer or device that is part of a network. At least two hubs are needed to form a network connection.

198

What is the difference between IPv4 and IPv6?

Reference answer

An IP address is a unique identifier for a device on a network. IPv4 (Internet Protocol version 4) uses a 32-bit address format, providing about 4.3 billion unique addresses. IPv6 (Internet Protocol version 6) uses a 128-bit address format, allowing for a vastly larger number of unique addresses (approximately 340 undecillion).

199

What is a Man-in-the-Middle (MitM) attack and how can it be prevented?

Reference answer

A MitM attack occurs when an attacker intercepts and manipulates communication between two parties. Preventive measures include using encryption (like SSL/TLS), employing secure protocols, and implementing strong authentication to ensure data confidentiality and integrity.

200

Name some services provided by the Application Layer in the Internet model.

Reference answer

The Application Layer of the OSI model comprises of a variety of services designed to help network applications function and promote smooth communication between end-user devices. Among the numerous services provided by the application layer, significant instances include the following: 1) Email services include protocols like SMTP for email transmission and POP3/IMAP for email retrieval. 2) File transfer services, such as FTP, SFTP, and SCP. 3) Web browsing and data retrieval are supported by HTTP and its secure equivalent, HTTPS. 4) Domain Name System (DNS) functionality is pivotal for translating domain names into corresponding IP addresses. 5) Remote access and terminal emulation services, exemplified by Telnet and SSH. 6) Network Management Protocols like SNMP. 7) Directory services such as LDAP are instrumental in facilitating user authentication and directory management. 8) Real-time communication and collaboration services, including VoIP protocols like SIP and instant messaging protocols like XMPP.

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Common Interview Questions for Wireless Network Analysts | SPOTO

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