Top Wi-Fi Engineer Job Interview Questions to Know

1

What knowledge do you have of network protocols?

Reference answer

With extensive experience in working with TCP/IP, I have honed my skills in resolving technical issues remotely by accessing the IP addresses of the user. I also possess expertise in installing and configuring wireless LAN technology, enabling seamless internet or intranet access within office spaces or designated areas. Moreover, my proficiency extends to deploying secure VPNs for multiple businesses, ensuring their data remains safeguarded and accessible only to people with the necessary authority. I recognise how these networking protocols represent fundamental components of standard technology crucial to a network's day-to-day functionality.

2

When would you use the FHSS technique, and when would you use the DSSS technique?

Reference answer

FHSS (Frequency Hopping Spread Spectrum) is used for low-interference environments or legacy systems, while DSSS (Direct Sequence Spread Spectrum) is preferred for higher data rates and robust performance in noisy settings.

3

What is active directory?

Reference answer

An active directory provides ways to handle the relationships and identities within a network. It allows the network administrator to manage domains, objects, and users in a network. The admin can create a user group and assign special access privileges to them for accessing specific directories on the server. The 3 main components of the active directory structure are - Domain - Trees - Forests

4

What is a MAC address?

Reference answer

A MAC (Media Access Control) address is used for uniquely identifying a device on a network. Also called the physical address or ethernet address, MAC addresses are 48-bit numbers that are present in the NIC of the devices. This is an address given by the manufacturer of the device. The MAC sub-layer of the data link layer makes use of the MAC addresses. They are 12-digit hexadecimal numbers, where the first 6 digits identify the manufacturer.

5

How do you configure wireless QoS for VoIP calls?

Reference answer

To configure wireless QoS for VoIP: - - Define a QoS policy for voice traffic. - Apply the policy to the appropriate WLAN or SSID. - Use priority tags (e.g., DSCP values) to prioritize voice packets. - Configure access points and controllers to enforce QoS settings.

6

What can routers do with their built-in console?

Reference answer

Routers have a built-in console that allows you to configure various settings, such as security and data logging. You can assign restrictions to computers, like what resources they are allowed access to or when they can browse the Internet. You can also impose restrictions on what websites are not visible across the entire network.

7

How do you handle network capacity forecasting and planning?

Reference answer

I handle network capacity forecasting and planning by analyzing current network usage, monitoring traffic patterns, and projecting future growth. I use historical data and industry benchmarks to identify potential bottlenecks and plan for necessary upgrades or expansions. Regular reviews and updates to the capacity plan ensure that the network can support the organization's evolving needs.

8

What is the purpose of the Cisco ASA firewall?

Reference answer

The ASA provides stateful firewall, VPN, and intrusion prevention services for network security.

9

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.

10

What is a DNS?

Reference answer

DNS stands for domain name system. Websites are accessed by their domain names such as google.com and yahoo.com. But these names are not understood by the computer. The DNS translates these names into IP addresses so that the browsers can load them for the users. DNS converts the hostname of the website into an IP address that is readable by the computer. The converting of hostnames into IP addresses is called forward lookup. Converting or resolving IP addresses into hostnames is called backward lookup.

11

What is the role of ARP?

Reference answer

ARP translates a known IP address into a physical MAC address. Devices on a local network need a MAC address to communicate directly. ARP is the protocol used to discover it. When a device needs to send data, it knows the destination IP address. It uses an ARP request to ask the network for the matching MAC address. The device with that IP address sends an ARP reply. This reply contains its MAC address. The requesting device can now send its data. ARP is an essential process for discovering addresses on a local network.

12

What is the purpose of the MPLS protocol?

Reference answer

MPLS (Multiprotocol Label Switching) directs data using labels for fast, efficient routing in service provider networks.

13

What Experience Do You Have with Cloud-Based WiFi Network Management Platforms?

Reference answer

Cloud-based WiFi network management platforms provide a centralized, anywhere-management for WiFi networks. With features like rapid deployment, centralized control, scalability, and cost-effectiveness, utilizing these platforms for managing WiFi 6/6E networks would prove advantageous. Personal experience includes using platforms like Cisco Meraki and Aruba Central to manage and optimize network operations.

14

Explain the concept of wireless network density and its impact.

Reference answer

Wireless network density refers to the number of devices or access points within a given area. High density can lead to increased competition for bandwidth and potential interference, requiring careful planning and management to ensure optimal performance.

15

Describe the differences between ad-hoc and infrastructure modes in wireless networking.

Reference answer

Ad-hoc mode allows direct device-to-device communication without an access point, while infrastructure mode uses an access point to manage connections.

16

What are nodes and links?

Reference answer

Node: Any communicating device in a network is called a Node. Node is the point of intersection in a network. It can send/receive data and information within a network. Examples of the node can be computers, laptops, printers, servers, modems, etc. Link: A link or edge refers to the connectivity between two nodes in the network. It includes the type of connectivity (wired or wireless) between the nodes and protocols used for one node to be able to communicate with the other.

17

Define anonymous FTP and describe its use in network management.

Reference answer

Anonymous FTP allows users to access files on a server without requiring a personalized login. It's often used for distributing public data, though security considerations are paramount. In my role, I've configured anonymous FTP for controlled environments while ensuring proper access restrictions.

18

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

Reference answer

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

19

Describe a time when you had to communicate technical information to a non-technical audience.

Reference answer

During a company-wide meeting, I explained the importance of network security to non-technical staff by using simple analogies, like comparing firewalls to locked doors. This approach helped everyone understand the critical role they play in maintaining our network's safety.

20

How do you perform network capacity planning?

Reference answer

Analyze current usage trends, forecast growth, and plan for bandwidth and hardware upgrades.

21

What tools do you use for network monitoring and management?

Reference answer

I primarily use SolarWinds and Nagios for network monitoring and management. These tools allow me to proactively identify and resolve issues, ensuring optimal network performance and security.

22

What is the purpose of the Palo Alto Networks Certified Network Security Engineer (PCNSE) certification?

Reference answer

PCNSE certifies skills in deploying and managing Palo Alto firewalls for network security.

23

How do you ensure Quality of Service in a VoIP network?

Reference answer

Use QoS policies to prioritize VoIP traffic, minimize jitter, and ensure low latency with bandwidth guarantees.

24

What are Nodes and Links?

Reference answer

Two or more computers form a network when some wire or fiber optics physically links them. In this configuration, the computers are referred to as nodes, and the link is the actual medium of communication, i.e., the physical medium.

25

What is the DNS?

Reference answer

DNS is the Domain Name System. It is considered as the devices/services directory of the Internet. It is a decentralized and hierarchical naming system for devices/services connected to the Internet. It translates the domain names to their corresponding IPs. For e.g. interviewbit.com to 172.217.166.36. It uses port 53 by default.

26

What is wireless communication?

Reference answer

Wireless communication refers to the transmission of data or voice signals without the use of physical connections (wires). It relies on electromagnetic waves (e.g., radio, microwave, infrared) to transfer information between devices.

27

Explain the concept of load balancing.

Reference answer

Load balancing distributes network traffic across multiple servers or links to optimize resource use and prevent overload.

28

What is Dynamic Transmit Power Control (DTPC)?

Reference answer

DTPC: Adjusts transmit power of APs and clients to ensure balanced communication and save battery life.

29

What EAP method do you prefer and why?

Reference answer

The candidate should state their preferred Extensible Authentication Protocol (EAP) method (e.g., EAP-TLS, PEAP) and justify based on security, ease of deployment, or compatibility.

30

What is handover in cellular networks?

Reference answer

Handover is the process of transferring an ongoing call or data session from one cell to another as the user moves. It ensures seamless communication without dropping connections as users move through different coverage areas.

31

How do cross cables differ from regular LAN cables? What is the LAN cable's maximum possible length?

Reference answer

Cross cable and standard LAN cables differ in the manner that the paired wires are joined to the connector (RJ45). The theoretical length is 100 meters, however, after you pass 80 meters, the signal loss may cause your speed to decline.

32

How do you analyze network traffic patterns?

Reference answer

I use tools like Wireshark, NetFlow analyzers, or network management software to collect and examine data on traffic volume, flow, sources, and destinations. I look for trends, spikes, or irregularities in the data to identify potential issues and optimize performance.

33

What is 802.1x?

Reference answer

- 802.1x: IEEE standard for port-based network access control, providing an authentication framework for wireless LANs. It authenticates devices wishing to attach to a LAN or WLAN through a central authority.

34

How can you discover network topology?

Reference answer

There are many ways to discover network topology and most of the ways you know determine your experience in the field. First, you can ping random IP addresses. If you do a tracert, you can discover router IP addresses. You can install a network traffic packet analyzer to read some of the traffic that passes between segments of the network. You can run an SNMP scanner and attempt to find open systems. Even at a basic level, you can plug a laptop into open data ports to see if you can connect to various servers and other desktops.

35

What is the frequency range of the 802.11g standard?

Reference answer

2.4GHz Frequency.

36

How can you identify and resolve IP address conflicts?

Reference answer

Use commands like ipconfig or arp -a to detect duplicates, then release/renew IPs or assign static addresses to resolve conflicts.

37

What is the significance of using channel width in wireless networks?

Reference answer

Channel width affects the data rate and bandwidth of a wireless network. Wider channels (e.g., 40 MHz, 80 MHz) provide higher throughput but can also increase interference. Properly selecting channel width helps balance performance and interference.

38

What Is Your Approach for Managing Interference on WiFi Networks, Particularly on 6 GHz Band?

Reference answer

Managing interference on WiFi networks is critical for optimal performance. On the 6 GHz band, the primary concerns comprise co-channel interference and adjacent channel interference. My approach includes conducting regular spectrum analysis, ensuring the network infrastructure is well-designed, carefully selecting WiFi channels, and effectively using WiFi 6/6E technologies like OFDMA and MU-MIMO. This helps in managing interference and ensuring a smooth, efficient network.

39

How Do You Prioritize Network Tasks?

Reference answer

Effective prioritization ensures critical tasks are addressed promptly. Candidates should describe their method for assessing task urgency and importance, and how they balance immediate needs with long-term projects.

40

Can you explain the function of a VLAN?

Reference answer

A VLAN is a group of devices that are on different physical networks but can communicate as if they were in the same network. VLANs improve network performance by segmenting the network, which reduces the need to send broadcasts and multicasts on the entire network. It also improves security by isolating sensitive data to a specific VLAN.

41

How is UWB (ultra-wideband) different from Bluetooth, FireWire and Wi-Fi?

Reference answer

- UWB is Radio Frequency technology that transmits binary data, using low energy and short duration impulses over a wide spectrum of frequencies. It delivers data over 15 to 100 meters and does not require a dedicated radio frequency. For example, a UWB signal centered at 5GHz typically extends across 4GHz and 6GHz. At longer distances, UWB data rates drop considerably. - Bluetooth:- The key difference among UWB and Bluetooth are of range, power, consumption and intended use. It is basically meant for short distances up to (10m). It is low power consuming than UWB. - Since FireWire is meant to deliver high speed, it is also designed to work with high power drain services. It therefore can provide much more power to the devices that connect to it. It can deliver up to 60 watts of energy. So the only difference here is of power it uses more power than UWB. - Wi-Fi really wasn't built to move audio and video, it was built for data traffic where if there's delay, while UWB is better suited for multimedia for a couple of reasons, i.e. for starters, it's throughput for surpasses that of Wi-Fi.

42

What cell edge and cell overlap would you survey for a voice deployment

Reference answer

-65 to -67 dBm

43

Which LAN cable types are commonly used? What is a cross cable?

Reference answer

"Cat 5" and "Cat 6" are the LAN cable types most often used. The speed limits for "Cat 5" and "Cat 6" are 100 Mbps and 1 Gbps, respectively. A cross table connects same-type devices for interaction without needing a switch or hub.

44

What are the HTTP and the HTTPS protocol?

Reference answer

HTTP is the HyperText Transfer Protocol which defines the set of rules and standards on how the information can be transmitted on the World Wide Web (WWW). It helps the web browsers and web servers for communication. It is a ‘stateless protocol' where each command is independent with respect to the previous command. HTTP is an application layer protocol built upon the TCP. It uses port 80 by default. HTTPS is the HyperText Transfer Protocol Secure or Secure HTTP. It is an advanced and secured version of HTTP. On top of HTTP, SSL/TLS protocol is used to provide security. It enables secure transactions by encrypting the communication and also helps identify network servers securely. It uses port 443 by default.

45

How does Ansible facilitate network automation?

Reference answer

Ansible uses playbooks to automate configuration across devices, supporting idempotent and agentless operations.

46

What is latency?

Reference answer

Latency is the time it takes for data to make a round trip. We measure latency in milliseconds. A low number is good. A high number is bad. You send a message and wait for a response. The time you wait is referred to as latency. It is the time for a signal to travel to a server and then come back to you. When playing an online game, low latency is crucial. High latency causes lag. It makes the game feel slow. The same applies to video calls. High latency makes conversations difficult. It is not the same as speed. Speed, or bandwidth, is how much data you can move at once. Latency refers to the time it takes for any piece of data to travel. You can have a fast connection with bad latency. This would feel like a big highway with a long delay at a traffic light.

47

What are the common hardware and software networking problems?

Reference answer

Common hardware networking problems: - Faulty hard drives - Damaged network interface cards (NICs) - Hardware initialisation issues - Inaccurate hardware configuration Common software networking problems: - Issues related to client-server interactions - Conflicts arising from application compatibility - Errors in configuration settings - Protocol mismatches that cause communication problems - Security concerns and vulnerabilities - Challenges related to user policies and rights management

48

What is subnetting, and how do you calculate subnets?

Reference answer

Subnetting is the process of dividing a larger IP network into smaller, more manageable sub-networks (subnets). This helps improve network performance and security. To calculate subnets, you determine the number of bits needed for the subnet mask to achieve the desired number of subnets and hosts per subnet. For example, to create four subnets from a Class C network (192.168.1.0/24), you would use a subnet mask of 255.255.255.192 (/26), which provides four subnets with 62 hosts each.

49

What is the difference between Wi-Fi and Ethernet?

Reference answer

Wi-Fi is a wireless technology using radio waves for connectivity, while Ethernet uses physical cables for wired, more stable connections.

50

What is the meaning of threat, vulnerability, and risk?

Reference answer

Threats are anything that can exploit a vulnerability accidentally or intentionally and destroy or damage an asset. An asset can be anything people, property, or information. The asset is what we are trying to protect and a threat is what we are trying to protect against. Vulnerability means a gap or weakness in our protection efforts. Risk is nothing but an intersection of assets, threats, and vulnerability. A+T+V = R

51

What is the significance of a cloud access security broker (CASB)?

Reference answer

A CASB enforces security policies between cloud users and providers, monitoring access and data.

52

What experience do you have with designing wireless mesh networks?

Reference answer

The candidate should describe their involvement in mesh network design, including node placement, routing protocols, and performance optimization.

53

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.

54

How do you manage network device configurations and backups?

Reference answer

I manage network device configurations and backups by using configuration management tools and automated backup solutions. This includes regularly backing up device configurations, maintaining version control, and storing backups in secure locations. Regular audits and updates ensure that configurations are up-to-date and can be quickly restored in case of device failures or configuration errors.

55

What is TCP/IP?

Reference answer

TCP is the Transmission Control Protocol and IP is the Internet Protocol.

56

Can you explain the purpose of ACLs (Access Control Lists) and how they are used?

Reference answer

ACLs (Access Control Lists) are used to define rules that control the flow of traffic in a network. They specify which packets are allowed or denied based on criteria such as source and destination IP addresses, ports, and protocols. ACLs are implemented on routers, switches, and firewalls to enhance network security, manage traffic, and enforce policies.

57

What are Ethernet LANs 10base2, 10base5, and 10baset?

Reference answer

- 10Base2: A contiguous cable segment length of 100 meters and a maximum of 2 segments are required for 10Base2: An Ethernet term that refers to a maximum transmission rate of 10 Megabits per second using baseband signaling. - 10Base5: 10Base5 is an Ethernet phrase that refers to 5 continuous segments with a maximum distance of 100 meters between them and a maximum transfer rate of 10 Megabits per second using baseband signaling. - 10BaseT: An acronym for Ethernet that refers to twisted-pair wiring and a top transfer rate of 10 Megabits per second.

58

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.

59

What is IP?

Reference answer

Each device (such as a computer or printer) in a computer network that uses Internet Protocol (IP) is assigned a numerical label known as an Internet Protocol address (IP address). The IP of your system or device uniquely identifies it from a large network of computers.

60

How do we prevent loops on the WLC?

Reference answer

- STP (Spanning Tree Protocol): Enabled to prevent network loops.

61

What is the purpose of IPv6 anycast addressing?

Reference answer

Anycast sends packets to the nearest node with the same address, used for load balancing and redundancy.

62

How do you keep your skills and knowledge up to date in the field of wireless engineering?

Reference answer

I regularly read publications like IEEE Spectrum and attend industry conferences like Mobile World Congress. I'm also a member of the Wireless Communications Association, which provides access to valuable resources and networking opportunities. Recently, I implemented a new network optimization tool I learned about at a conference, which increased our system efficiency by 15%. Staying updated is crucial for my role, as it directly impacts my ability to innovate and lead effectively.

63

What is data encapsulation?

Reference answer

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

64

What is the purpose of a wireless access point (AP)?

Reference answer

A wireless access point (AP) provides wireless connectivity to devices within a network. It acts as a bridge between wireless clients and the wired network, allowing devices to connect to the network without physical cables.

65

Can you describe your experience with cloud networking and hybrid environments?

Reference answer

I have experience with cloud networking and hybrid environments, including configuring and managing network resources on platforms like AWS, Azure, and Google Cloud. This includes setting up VPNs, virtual networks, and security groups to ensure seamless connectivity between on-premises and cloud environments. Hybrid environments require careful integration and management to ensure performance, security, and reliability.

66

How much overhead is added for WEP, TKIP and CCMP?

Reference answer

WEP : 8 Octet [4-IV + 4-ICV] TKIP : 20 Octet [4-IV + 4-EIV + 8-MIC + 4-ICV] CCMP : 16 Octet [8-CCMP Header + 8-MIC]

67

What is STP?

Reference answer

STP (Spanning Tree Protocol) prevents loops in switching.

68

Which Diffie Hellman Group is Most Secure?

Reference answer

The most secure Diffie-Hellman group is currently considered to be Group 24 (2048-bit ECP) or higher, offering stronger encryption and resistance to attacks. Apart from that the security of a Diffie-Hellman (DH) group depends on the size and type of the underlying prime numbers or elliptic curves used.

69

Describe the concept of wireless spectrum and its importance.

Reference answer

Wireless spectrum refers to the range of radio frequencies used for wireless communication. It is important because it determines the capacity, coverage, and performance of wireless networks. Proper management of spectrum helps avoid interference and optimize network performance.

70

Explain the concept of frequency reuse.

Reference answer

Frequency reuse is a technique used in cellular networks to maximize spectrum efficiency by allowing the same frequencies to be used by different cells in a network. These cells are geographically separated to minimize interference.

71

What is NAT?

Reference answer

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

72

What is a DDoS attack?

Reference answer

A DDoS (Distributed Denial of Service) attack overwhelms a target with traffic from multiple sources, disrupting normal service.

73

What is the role of address in a packet traveling through a datagram network?

Reference answer

The address field in a datagram network is end-to-end addressing.

74

What do you mean by a network?

Reference answer

A network can be considered as a set of devices of systems that are connected. They can communicate and share information. Devices such as computers, laptops, servers, and printers can be connected through networks like LAN (Local Area Network) and WAN (Wide Area Network).

75

What are the common issues that can affect wireless signal quality?

Reference answer

Common issues include interference from other wireless devices, physical obstructions (e.g., walls, furniture), incorrect access point placement, and network congestion. Addressing these issues often involves optimizing channel settings, adjusting AP locations, and managing network traffic.

76

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

Reference answer

When 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 client's needs and expectations. Once I've gathered and clarified all this information, I'll then proceed to formulate a solution that aligns with their specific needs. I'll use this process to ensure that the end result meets or exceeds the client's expectations and provides the best possible network solution tailored to their specific goals.

77

How do you find answers to problems you can't solve?

Reference answer

Every engineer will come across an issue that he can't figure out. Network engineering is difficult, so no one expects you to have the answers at all times. However, it's important that you know how to find answers when you need them. The first obvious answer is to Google. Google also leads you to some popular spots for network engineers and other IT people. Stack Overflow is a popular forum where you can ask, answer and read questions and answers. You can also find help in books and manuals that come with the hardware you purchase.

78

Explain the purpose of the ARP protocol.

Reference answer

The ARP protocol resolves IP addresses to MAC addresses for communication within a local network segment.

79

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.

80

What is the purpose of a subnet mask?

Reference answer

A subnet mask is used to divide an IP address into network and host portions, enabling efficient routing and network segmentation.

81

Can you explain the purpose of a DMZ (Demilitarized Zone) in network security?

Reference answer

A DMZ (Demilitarized Zone) is a separate network segment that acts as a buffer zone between an internal network and external networks, such as the internet. It hosts publicly accessible services, such as web servers and email servers, while isolating them from the internal network. This setup enhances security by reducing the risk of external threats penetrating the internal network.

82

What is the difference between TCP and UDP?

Reference answer

TCP is connection-oriented and reliable; UDP is connectionless and faster but unreliable.

83

What are Private and Special IP addresses?

Reference answer

Private Address: For each class, there are specific IPs that are reserved specifically for private use only. This IP address cannot be used for devices on the Internet as they are non-routable. | IPv4 Class | Private IPv4 Start Address | Private IPv4 End Address | |---|---|---| | A | 10.0.0.0 | 10.255.255.255 | | B | 172.16.0.0 | 172.31.255.255 | | C | 192.168.0.0 | 192.168.255.255 | Special Address: IP Range from 127.0.0.1 to 127.255.255.255 are network testing addresses also known as loopback addresses are the special IP address.

84

How many layers does TCP/IP comprise, and what are they?

Reference answer

TCP/IP consists of four layers: the network interface, internet, transport, and application layers. Each layer serves distinct functions, from handling physical transmission to managing end-to-end communication. This layered approach facilitates modular design and troubleshooting.

85

What is the purpose of using multiple SSIDs on an access point?

Reference answer

Multiple SSIDs allow an access point to broadcast different network names, enabling the segregation of traffic for various user groups (e.g., employees, guests). It helps in managing network access and applying different security policies for each SSID.

86

What are private IP addresses used for?

Reference answer

Private IP addresses are assigned for use on intranets. These addresses are used for internal networks through the IP address and are not routable on external public networks. This ensures that no conflicts are present among internal networks.

87

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

Reference answer

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.

88

What considerations do you take into account when designing a multi-cloud networking architecture?

Reference answer

When designing multi-cloud networking architectures, I consider the following: - Interoperability between different cloud providers - Data transfer costs between clouds and on-premises systems - Consistent security policies across all environments - Network performance and latency between clouds - Redundancy and failover mechanisms - Compliance with data sovereignty regulations - Unified monitoring and management tools for all cloud environments

89

What is the three-way handshake in TCP?

Reference answer

The three-way handshake is the process of establishing a TCP connection: SYN, SYN-ACK, ACK.

90

What are some common network performance issues you have encountered, and how did you resolve them?

Reference answer

One common issue I've encountered is network congestion, which I resolved by implementing Quality of Service (QoS) policies to prioritize critical traffic. Additionally, I addressed latency problems by optimizing routing paths and upgrading network hardware.

91

What are the layers contained in the OSI reference model?

Reference answer

There are seven layers in the OSI Reference Models: - The physical layer converts data bits into radio signals. - The data link layer is where packets are encoded and decoded into bits for node-to-node transfer. - The network layer transfers data sequences from one node to another. - The transport layer transfers data between nodes and acknowledges successful transmissions. - The session layer establishes and terminates local and remote application connections. - The presentation layer transforms data into a form that's accepted by the application layer. - The application layer interacts with the application to enable tasks like email, data transfer, etc.

92

What do the terms '10' and 'Base' refer to in networking?

Reference answer

The 10 refers to the data transfer rate, which in this case is 10 Mbps. The term 'Base' refers to baseband, as opposed to broadband.

93

How do you stay updated on the latest networking technologies and trends?

Reference answer

I follow industry blogs, attend webinars, pursue certifications, and participate in forums.

94

What is a network loop, and how can it be prevented?

Reference answer

A network loop occurs when packets circulate endlessly due to redundant paths, causing broadcast storms. It is prevented using STP (Spanning Tree Protocol).

95

What is a transparent bridge?

Reference answer

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

96

Explain the concept of a softphone in VoIP communication.

Reference answer

A softphone is software that emulates a phone, enabling VoIP calls from a computer or mobile device.

97

Explain the purpose of the ICMP protocol.

Reference answer

ICMP is used for network diagnostics and error messages, such as unreachable hosts or time exceeded, facilitating troubleshooting.

98

Cisco 5520 Wireless Controller supports how many clients and APs?

Reference answer

Supports Up to 1500 Access Points.

99

How do domains work?

Reference answer

When we install Active Directory, a domain is formed. It's a security barrier that controls computers inside of it. Using a domain, you can centrally manage computers and control them with group policies.

100

How would you put in place network security procedures?

Reference answer

There are multiple effective approaches to achieve ensure your network is secure. First, I would ensure that all work computers and devices are installed with a reliable and up-to-date anti-virus programme. Secondly, I'd recommend setting up and configuring appropriate firewalls to bolster network security. I would also consider implementing user authentication protocols to help enhance the protection of the network. By combining these measures, a highly secured network can be established.

101

Have you worked in heterogeneous environments and multiple server and client platforms?

Reference answer

The obvious answer to this question is yes or no, but you should elaborate if the answer is yes. Most networking environments use a combination of Windows and Linux servers and desktops. Usually, network engineers prefer Linux servers and work with Windows and Linux desktops. Occasionally, you might have some Mac desktops as well to work with.

102

What is a Proxy Server?

Reference answer

A proxy server is a computer or system that works like a middleman between your device and the internet. It is used for better security, privacy, control, and faster access to some websites. If you want to open a website on your browser, you just type the address, and it will open the website. But when a proxy server is used, your request first goes to the proxy server, which then sends it to the website. Why do companies use a proxy server? There are many reasons for using a proxy server. Here are some important ones: - Security: A proxy server hides the real IP Address of users. It can help protect systems from hackers. - Control: Companies use it to block websites like games or social media during work hours. - Faster Browsing: Some proxy servers save copies of websites in memory. If the user reloads this website, the server will serve it faster. - Privacy: A proxy server can hide the real identity of the user by showing its own server.

103

Please Share Your Experience Configuring and Managing WiFi 6/6E Networks?

Reference answer

While it can be challenging when deploying a new technology, with thorough planning, training, and learning, configuring and managing WiFi 6/6E networks can be accomplished smoothly. From a technical standpoint, both these networks need to be configured correctly to leverage the benefits to their full potential. That involves properly setting up MU-MIMO, ensuring the use of 1024-QAM where applicable, and ensuring the network is properly segmented, among other things.

104

Can you give examples of how youâ€™ve used network visualization professionally?

Reference answer

Network visualization tools allow network engineers to monitor network and data performance, including components like routers and servers, by using visual depictions of networks and data flows. Understanding visualization tools can help you find issues, simplify network planning, and complete other tasks that can reduce downtime or potential costs, so employers may want to ensure you have a grasp of visualization techniques.

105

Describe your experience with routing protocols such as OSPF, EIGRP, or BGP.

Reference answer

I have extensive experience with OSPF, EIGRP, and BGP, having implemented and optimized these protocols in various enterprise environments. For instance, I successfully configured BGP for a multi-homed network to ensure redundancy and load balancing.

106

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

107

Describe the benefits of load balancing in a network.

Reference answer

Load balancing improves reliability, prevents overload, and optimizes resource utilization.

108

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

Reference answer

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

109

How are Network types classified?

Reference answer

Network types can be classified and divided based on the area of distribution of the network. The below diagram would help to understand the same:

110

Explain the role of the ACL (Access Control List) on a Cisco device.

Reference answer

ACLs filter traffic based on IP addresses, protocols, or ports, used for security and traffic management.

111

What tools do you use for network monitoring and management?

Reference answer

I use a variety of tools for network monitoring and management, including SolarWinds, Nagios, PRTG Network Monitor, and Wireshark. These tools provide real-time monitoring, alerting, and detailed analysis of network performance and traffic. They help identify and resolve issues quickly, ensure network uptime, and optimize network performance.

112

How do you ensure compliance with industry standards and regulations in your network designs?

Reference answer

I stay updated with industry standards and regulations by regularly attending training sessions and reviewing compliance documentation. I also conduct periodic audits to ensure our network designs meet all necessary requirements, proactively addressing any potential issues.

113

How do you plan for network scalability?

Reference answer

Design with modular hardware, use hierarchical topologies, and plan for IP address growth and bandwidth upgrades.

114

What distinguishes communication from transmission?

Reference answer

Transmission entails the physical movement of information, which raises concerns about things like bit polarity, synchronization, clocks, etc. Communication is the complete information exchange between two communication media.

115

What is Wi-Fi and what is WiMAX?

Reference answer

- Wi-Fi: Wireless Fidelity, a technology that uses radio waves for high-speed network connectivity based on IEEE 802.11 standards. Devices include PCs, laptops, video game consoles, phones, tablets, smart TVs, and more. - WiMAX: Worldwide Interoperability for Microwave Access, referenced by IEEE 802.16, commonly termed 4G. It provides wide area network access and uses OFDM modulation.

116

What is the function of WLAN on WLC?

Reference answer

- WLAN: Similar to SSID, required for client association with the network.

117

How do you implement and manage Access Control Lists (ACLs)?

Reference answer

Implementing ACLs involves defining rules that control network traffic based on IP addresses, protocols, or ports. This includes determining security policies, creating ACL entries, applying them to network interfaces, and regularly reviewing and updating them to adapt to changing security needs.

118

What is your experience as a Network Engineer?

Reference answer

If you've previously worked as a Network Engineer, summarize your experience. If not, discuss relevant skills and projects and how they'll relate to your day-to-day activities on the job. Looking over your resume will help you prepare for this question. Note the highlights so you can be ready to talk about them if asked to do so. You'll also want to include information that's not listed on your resume. Otherwise, it may sound like you're just repeating those details. Instead, discuss what you learned in previous positions and how those experiences relate to your current skill set. You can also mention any relevant courses you've taken or certifications you've earned.

119

Can you work as a team?

Reference answer

Most network admins need to work as a team. The interviewer will ask you questions regarding team environment to make sure you are comfortable working with other team members. Some people cannot work in a team and need to be in their own environment. If the company has a large network, however, you will probably need to work as a team with other engineers.

120

What's your experience with various wireless monitoring tools? Do you have a preferred tool or a tool with the most experience?

Reference answer

The candidate should list tools they have used (e.g., Wireshark, Ekahau, AirMagnet) and explain their preferred tool based on features, ease of use, or past success.

121

What is the distinction between an "extended" and "standard" ACI (Access Control List)?

Reference answer

Extended ACLs are source- and destination-based. Standard ACLs are source-based.

122

How does SDN (Software-Defined Networking) work?

Reference answer

SDN separates the control plane from the data plane, centralizing network management via software controllers.

123

What does the OSI Session Layer provide?

Reference answer

The OSI Session Layer provides the protocols and means for two devices on the network to communicate with each other by holding a session. This includes establishing the session, managing data exchange during the session, and terminating the session upon completion.

124

What is the frequency range of the 802.11g standard?

Reference answer

- 2.4GHz Frequency.

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

Describe the generic EAP process

Reference answer

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

127

What is ESS?

Reference answer

- ESS (Extended Service Set): Created by connecting multiple BSSs via a distribution system, allowing larger coverage and seamless client roaming.

128

Describe the difference between a star and a mesh topology.

Reference answer

Star topology connects all devices to a central hub, while mesh topology connects devices directly to multiple others for redundancy.

129

What measurements would you take to protect an internal network from external threats?

Reference answer

The candidate should describe measures such as implementing firewalls, intrusion detection and prevention systems (IDPS), using virtual private networks (VPNs), applying access control lists (ACLs), conducting regular security audits, and ensuring network segmentation to isolate sensitive data.

130

What's your experience with disaster recovery and business continuity planning?

Reference answer

I've been involved in DR planning from the design phase. The key questions I ask are: what's our RTO—how long can the network be down?—and what's our RPO—how much data can we afford to lose? For a financial services client, both of those were measured in minutes, so we designed with active-active redundancy and real-time replication. For less critical operations, we might have RTO measured in hours and use regular backups. Specifically, I've implemented redundant links between data centers so traffic can automatically failover. I've also worked on documenting recovery procedures and testing them regularly because a plan that's never tested doesn't work. We do a quarterly DR test where we actually fail over the network to the backup data center and measure how long services are down. Those tests have revealed issues we would have missed in a real crisis. One thing I learned the hard way is that having backups isn't enough—you need to test restoration regularly because I've seen situations where backups were corrupted and nobody knew until they tried to use them.

131

What is multicast routing?

Reference answer

Multicast routing is a form of broadcasting that sends a message to a selected group of recipients rather than transmitting it to all users on a subnet.

132

Explain the OSI model.

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: Physical, Data Link, Network, Transport, Session, Presentation, and Application.

133

What are the advantages and disadvantages of piggybacking?

Reference answer

Advantages of Piggybacking: The major advantage of piggybacking is the better use of available channel bandwidth. Disadvantages of Piggybacking: The major disadvantage of piggybacking is additional complexity and if the data link layer waits too long before transmitting the acknowledgment, then re-transmission of the frame would take place.

134

Can you explain the difference between routing and switching?

Reference answer

Routing and switching are fundamental networking concepts. Routing involves determining the best path for data packets to travel from the source to the destination in different networks. On the other hand, switching involves moving data packets between devices within the same network. While routers operate at the network layer (Layer 3) of the OSI model, switches operate at the data link layer (Layer 2).

135

What is the 802.11g standard?

Reference answer

Launched in 2003, 802.11g combines the best of both 802.11a and 802.11b. It operates in the 2.4 GHz frequency band and uses OFDM, offering a maximum data rate of 54 Mbps. It is backward compatible with 802.11b devices.

136

Describe the purpose of a captive portal in wireless networking.

Reference answer

A captive portal is a web page that users are redirected to when connecting to a public or guest wireless network. It typically requires users to authenticate or accept terms of service before granting access to the internet or network resources.

137

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

Reference answer

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

138

Difference between Wi-Fi and Bluetooth?

Reference answer

- Wi-Fi vs Bluetooth: Wi-Fi is for high-speed internet access; Bluetooth is for short-range communication between devices.

139

What is the difference between CAPWAP and LWAPP?

Reference answer

- CAPWAP vs LWAPP: CAPWAP supports both IPv4 and IPv6, provides better security, and uses DTLS, whereas LWAPP only supports IPv4 and is less secure.

140

What is the purpose of network slicing in 5G networks?

Reference answer

Network slicing creates isolated virtual networks for different services, optimizing performance.

141

What is Authorization?

Reference answer

Authorization provides capabilities to enforce policies on network resources after the user has gained access to the network resources through authentication. After the authentication is successful, authorization can be used to determine what resources is the user allowed to access and the operations that can be performed.

142

Explain the concept of airtime fairness in wireless networks.

Reference answer

Airtime fairness ensures that all devices connected to a wireless network receive an equal opportunity to transmit data. It prevents a single device from monopolizing network resources and improves overall network performance and user experience.

143

What is the purpose of a proxy server?

Reference answer

Proxy servers primarily prevent external users from identifying the IP addresses of an internal network. Without knowledge of the correct IP address, the physical location of the network cannot be determined. This makes network locations more secure.

144

Define HTTPS protocol?

Reference answer

The full form of HTTPS is a Hypertext transfer protocol secure. It is an advanced version of the HTTP protocol. Its port number is 443 by default. It uses SSL/TLS protocol for providing security.

145

What is ICMP?

Reference answer

The Internet Control Message Protocol (ICMP) is designed for reporting errors and information related to network connectivity issues to the origin of the failed transmission. It is primarily utilized by network administrators to diagnose and resolve issues related to Internet connectivity. The ICMP protocol operates by generating and transmitting messages to the originating IP address, signaling the inability to access an Internet gateway for the purpose of delivering packets. The process involves the transmission of datagrams that comprise an IP header, which encapsulates the ICMP data. Error messages such as: - Destination unreachable - Source quench message - Redirection message - Time exceeded message - Parameter problem

146

Explain the difference between 2.4 GHz and 5 GHz frequency bands.

Reference answer

The 2.4 GHz band offers longer range but is more susceptible to interference and congestion from other devices (e.g., microwaves, Bluetooth). The 5 GHz band provides faster speeds and less interference but has a shorter range and lower penetration through obstacles.

147

How would you troubleshoot a slow network connection?

Reference answer

Check bandwidth usage, test for packet loss, analyze QoS settings, inspect for malware, and verify hardware performance.

148

What is a VLAN and Why do We Use it?

Reference answer

A VLAN (Virtual Local Area Network) is a logical segmentation of a physical network that separates broadcast domains within a switch. There are various reasons to use Virtual LANs. First of all VLANs are important for security. We can divide different departments traffic with VLANs. This also provides broadcast traffic reduce. Instead of one large network, we can divide our network into smaller parts. By doing this network management become easier. Follow-up Question: What is the difference between an access port and a trunk port? Access Port is a port which belongs to one VLAN and carries traffic for that VLAN. It is used for end devices like PCs and printers. Trunk Port is a port that carries traffic for multiple VLANs between switches. VLAN information is preserved using VLAN tagging (802.1Q). Follow-up Question: Can devices in different VLANs communicate directly? No, they cannot. Because the devices in different VLANs are in separate broadcast domains. Here, Inter-VLAN Routing is required. There are two ways to use Inter-VLAN Routing: Using a Router or using a Layer 3 switch to use Switch Virtual Interfaces.

149

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.

150

What is Multicast?

Reference answer

Multicast is a method of group communication where the sender sends data to multiple receivers or nodes present in the network simultaneously. Multicasting is a type of one-to-many and many-to-many communication as it allows sender or senders to send data packets to multiple receivers at once across LANs or WANs. This process helps in minimizing the data frame of the network. For more details please read Multicasting in computer network article.

151

What is IP Spoofing?

Reference answer

IP Spoofing is essentially a technique used by hackers to gain unauthorized access to Computers. Concepts of IP Spoofing were initially discussed in academic circles as early as 1980. IP Spoofing types of attacks had been known to Security experts on the theoretical level. It was primarily theoretical until Robert Morris discovered a security weakness in the TCP protocol known as sequence prediction. Occasionally IP spoofing is done to mask the origins of a Dos attack. In fact, Dos attacks often mask the actual IP addresses from where the attack has originated from.

152

What is the difference between Bluetooth and Wi-Fi?

Reference answer

| Bluetooth | Wifi | |---|---| | Bluetooth has no full form. | While Wi-Fi stands for Wireless Fidelity. | | It requires a Bluetooth adapter on all devices for connectivity. | Whereas it requires a wireless adapter Bluetooth for all devices and a wireless router for connectivity. | | Bluetooth consumes low power. | while it consumes high power. | | The security of Bluetooth is less in comparison to the number of Wi-Fi. | While it provides better security than Bluetooth. | | Bluetooth is less flexible means these limited users are supported. | Whereas Wi-Fi supports a large number of users. | | The radio signal range of Bluetooth is ten meters. | Whereas in Wi-Fi this range is a hundred meters. | | Bluetooth requires low bandwidth. | While it requires high bandwidth. |

153

Explain the term Jitter.

Reference answer

Jitter refers to a "packet delay variance," which is a problem when multiple packets of data encounter multiple delays in the network, and the data at the acceptor application is time-critical, i.e., audio or video data. It is calculated in milliseconds and is described as interference with the normal process of sharing data packets.

154

Describe the use of nslookup and dig in troubleshooting.

Reference answer

nslookup and dig query DNS servers to resolve domain names to IP addresses, helping diagnose DNS issues.

155

What are the different types of wireless propagation?

Reference answer

The three main types of propagation are: Line-of-Sight (LOS): Signals travel directly from the transmitter to the receiver with no obstacles. Non-Line-of-Sight (NLOS): Signals are obstructed by obstacles and rely on reflections, diffraction, or scattering. Groundwave/Surface wave: Signals propagate close to the earth's surface.

156

What is the significance of change management in network administration?

Reference answer

Change management ensures structured updates to minimize disruptions and maintain network stability.

157

Describe your experience with wireless networking and troubleshooting Wi-Fi issues.

Reference answer

I have extensive experience designing and implementing wireless networks, ensuring optimal coverage and performance. For troubleshooting Wi-Fi issues, I use tools like Ekahau and Wireshark to diagnose and resolve connectivity problems, resulting in a 40% improvement in network reliability.

158

What data units are used at each layer of the TCP/IP protocol suite?

Reference answer

- Message: The data unit created at the application layer. - Segment or User Datagram: The data unit created at the transport layer. - Datagram: The data unit created at the network layer.

159

How do you troubleshoot a wireless network issue where devices are unable to connect?

Reference answer

To troubleshoot wireless connectivity issues: - - Check the SSID and password for correctness. - Verify that the access point is powered on and operational. - Ensure there is no interference from other devices or physical obstructions. - Check for IP address conflicts and DHCP settings. - Review the access point's configuration and firmware for updates.

160

What is a layer?

Reference answer

A layer divides the PDU (protocol data unit) process entirely logically. They specify the method by which data is sent through a network from one machine to another.

161

What is a VPN?

Reference answer

A VPN is a Virtual Private Network. It creates a secure path over the internet, like a tunnel, to connect to a remote server.

162

What is 10Base2?

Reference answer

10Base2 defines the data transfer rate, i.e., 10Mbps, where Base is the "Baseband" and T defines the cable type. The IEEE 802.3a standard defines 10Base2, which includes data transmission rates of 10Mbps and a maximum segment length of 185 meters through the utilization of RG-58 coaxial cable. The 10Base2 protocol is characterized by a physical bus topology and employs BNC connectors that are equipped with 50-ohm terminators at both ends of the cable. It is necessary to ground one of the physical ends of every segment.

163

What types of challenges do you face most often when designing networks?

Reference answer

The candidate should discuss common design challenges like coverage gaps, interference, capacity planning, or scalability issues.

164

Describe the differences between imperative and declarative automation.

Reference answer

Imperative specifies step-by-step commands, while declarative defines the desired end state.

165

What is IBSS and BSS?

Reference answer

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

166

Explain what a proxy server is

Reference answer

A proxy server takes on the responsibility of accessing and retrieving data on behalf of users, much like how a DNS server caches website addresses. Additionally, it keeps a record of websites, distinguishing between those that are whitelisted or banned, thereby shielding users from easily avoidable viruses.

167

What is the purpose of RIP, OSPF, and EIGRP?

Reference answer

RIP (Routing Information Protocol) uses hop count for path selection, OSPF (Open Shortest Path First) uses link-state algorithms for scalability, and EIGRP (Enhanced Interior Gateway Routing Protocol) uses composite metrics for efficient routing.

168

Describe the purpose of a network firewall.

Reference answer

A firewall filters traffic based on security rules to protect against unauthorized access.

169

How do you handle network capacity planning and performance optimization?

Reference answer

I handle network capacity planning by analyzing current usage patterns and forecasting future demands to ensure scalability. For performance optimization, I regularly monitor key metrics and implement adjustments to maintain optimal network efficiency.

170

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

171

Have you implemented MIMO processes before?

Reference answer

The candidate should confirm experience with MIMO (Multiple Input Multiple Output) technologies, including antenna configurations and performance improvements.

172

What is the difference between ipconfig and ifconfig commands?

Reference answer

The ipconfig command stands for Internet protocol configuration that is used for configuring networking devices on Windows machines. All the TCP/IP network summary data can be displayed through this command using the command line. It is also used for refreshing the settings of Dynamic Host Configuration Protocol (DHCP) and Domain Name System (DNS). The ifconfig stands for interface configuration. The command is used for configuring and managing the network interface parameters on the TCP/IP network. The network interface IP addresses can be viewed with the help of this command. The command is used on MAC, LINUX and Unix operating systems.

173

In which OSI layer is the header and trailer added?

Reference answer

At the Data link layer trailer is added and at the OSI model layer 6,5,4,3 added header.

174

How do you optimize network performance?

Reference answer

Use QoS, load balancing, caching, and regular monitoring to reduce latency and improve throughput.

175

A user reports they cannot access the internet. What are the first three things you would check?

Reference answer

Look for a systematic approach, starting with basic connectivity checks like verifying the network cable and IP address. They should also mention checking the default gateway and DNS settings.

176

Explain the TCP three-way handshake.

Reference answer

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

177

How does traceroute work?

Reference answer

Traceroute sends packets with incrementing TTL values to map the path to a destination, revealing each hop's IP address and latency.

178

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.

179

Can You Explain Your Understanding of 1024-QAM Modulation in WiFi 6 and How It Improves Data Transfer Rates?

Reference answer

1024-QAM (Quadrature Amplitude Modulation) is a method used in WiFi 6 to achieve higher throughput. By allowing more data to be packed into each signal transmitted, it results in increased data rates. Compared to 256-QAM used in WiFi 5, 1024-QAM can deliver up to 25% more data, significantly enhancing network performance, especially in environments demanding high data transfer rates.

180

What is an IP address?

Reference answer

An IP address is a unique numerical label assigned to each device in a network to identify and locate it.

181

Can you explain the concept of multicast and how it is used in networking?

Reference answer

Multicast is a communication method where data is transmitted from one source to multiple destinations simultaneously. It is used in networking to efficiently deliver data, such as video streams or real-time updates, to multiple recipients without duplicating the data for each recipient. Multicast reduces network bandwidth usage and improves performance for applications that require simultaneous data delivery to multiple users.

182

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

183

Can you discuss how you perform a network audit and why it is important?

Reference answer

I conduct network audits by reviewing system logs, analyzing configuration settings, and verifying compliance with security standards. This process helps identify potential weaknesses and opportunities for improvement. Regular audits are essential to ensure that the network remains secure, efficient, and aligned with industry best practices.

184

Explain the difference between static and dynamic routing.

Reference answer

Static routing uses manually configured routes, while dynamic routing uses protocols like OSPF or EIGRP to automatically update routes based on network changes.

185

What is a node?

Reference answer

A node is a point at which you establish a connection. This network component is how you'll send, receive and forward electronic information. A device connected to your network can also be a node. For example, if your network consisted of two computers, two printers, and a server, there'd be five nodes on your network.

186

Explain the concept of Infrastructure as Code (IaC) in network automation.

Reference answer

IaC manages network infrastructure through code, enabling version control and repeatable deployments.

187

Define Digital Signatures?

Reference answer

As the name sounds are the new alternative to signing a document digitally. It ensures that the message is sent to the intended use without any tampering by any third party (attacker). In simple words, digital signatures are used to verify the authenticity of the message sent electronically. OR A digital signature is a mathematical technique used to validate the authenticity and integrity of a message, software, or digital document.

188

What is the 802.11ac standard?

Reference answer

Also known as Wi-Fi 5, 802.11ac was introduced in 2013. It operates in the 5 GHz frequency band and uses multi-user MIMO (MU-MIMO) technology to achieve a maximum data rate of up to 6.93 Gbps. It provides better performance, range, and capacity than previous standards and is backward compatible with 802.11a, 802.11b, 802.11g, and 802.11n devices.

189

How do you monitor network traffic?

Reference answer

Use tools like SNMP, NetFlow, or packet analyzers to track bandwidth, errors, and patterns.

190

What is ping and how is it used in troubleshooting?

Reference answer

Ping checks host availability and measures latency.

191

What are port numbers? What are well-known ports?

Reference answer

An IP address works well with the machines and systems but it doesn't necessarily tell you which application or service on that machine must handle the request. And that is why, Port numbers are used. So basically, a port identifies a specific process or service running on a host. For example: 192.168.1.10:443 Here, 192.168.1.10 is the device, and 443 tells the system to route the request to the HTTPS service. This combination of IP address and port is called a socket, and it uniquely identifies a communication endpoint. Port numbers are divided into ranges: - 0–1023 - well-known ports which are system-level services - 1024–49151 - registered ports - 49152–65535 - dynamic/ephemeral ports used temporarily by clients Here are some well-known ports that you should keep in mind: - HTTP - 80 - HTTPS - 443 - FTP - 21 (control), 20 (data) - SSH - 22 - Telnet - 23 - SMTP - 25 - DNS - 53 - DHCP - 67/68 - POP3 - 110 - IMAP - 143 - SNMP - 161 Also remember! TCP and UDP handle ports separately. So port 53 (DNS) can work over both TCP and UDP. You can be asked this question as a follow-up during an interview: Q. Can two services use the same port? Your ans: Not on the same protocol at the same time. However, TCP:80 and UDP:80 are treated as separate, so both can work simultaneously.

192

Describe a time you solved a significant wireless network interference problem. What was your approach?

Reference answer

At Vodacom, I encountered significant interference issues affecting a critical deployment in a high-density area. I conducted a thorough site survey using spectrum analysis tools and discovered overlapping channels. I recommended a channel reallocation strategy and deployed additional access points to improve coverage. This reduced signal drops by 60%, significantly enhancing user experience. This experience taught me the importance of thorough site assessments and flexible problem-solving.

193

Can you give an example of working on a project with a team?

Reference answer

Networking teams are becoming more collaborative with other teams, such as development teams, with different team members working together toward a common project goal. This question is a good time for you to talk about your teamwork skills and give examples of when you collaborated with other team members or other computer and IT groups in your company and what you achieved. Your previous experience is a good indicator of how you can work within a team environment when you join a new company or organization.

194

What is the function of a wireless network management system (WMS)?

Reference answer

A wireless network management system (WMS) provides centralized control and monitoring of wireless network components. It helps manage configuration, performance, security, and troubleshooting, offering insights and analytics to optimize network operations.

195

Discuss a situation where you had to collaborate with other IT teams to solve a network-related problem.

Reference answer

I worked with security to configure firewall rules and with server teams to resolve a DNS misconfiguration.

196

Explain the purpose of BGP in routing.

Reference answer

BGP (Border Gateway Protocol) is an exterior gateway protocol used for routing between autonomous systems on the internet.

197

What's the difference between a hub, switch, and router?

Reference answer

A hub broadcasts data to every port on the network and is the least complicated of these devices. Switches are similar to hubs but are more efficient by dynamically creating connections and providing data only to the port requested. Routers come in all shapes and sizes and are the most complicated of these three devices. Their purpose is to route network traffic.

198

How do you stay current with networking technologies and trends?

Reference answer

I subscribe to a few industry newsletters like Packet Pushers and follow some network engineers on Twitter who post about emerging trends. I've also gotten certifications like my CCNA, and I'm working toward my CCNP, which forces me to learn new technologies systematically. I tinker in my home lab—I have a few old routers and switches I practice on, and I sometimes spin up virtual network environments using GNS3 or Cisco's VIRL to experiment with new configurations before implementing them at work. I also attend a local networking meetup once a month where engineers from different companies share what they're working on. That exposure to what other organizations are doing helps me think about what might be relevant for us. Right now, I'm particularly interested in network automation and SDN because I see it becoming more mainstream, so I've started learning Python and Ansible.

199

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

Reference answer

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

200

What is the infrastructural mode of Wi-Fi?

Reference answer

The infrastructural mode of Wi-Fi is a setup where devices connect via a central access point, which manages network traffic and provides connectivity to other networks, such as the internet.

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