Top 250 Networking Interview Questions and Answers

Latency is the time taken for a signal to travel from one point to another, while delay is the time taken for a signal to be processed.

• Latency is the time taken for a signal to travel from one point to another, usually measured in milliseconds.

• Delay is the time taken for a signal to be processed, which can be affected by factors such as network congestion or processing time.

• Latency can be reduced by improving network infrastructure, while delay can be reduced by optimizing pr...read more

Broadband refers to high-speed internet access that is always on and faster than traditional dial-up access.

• Broadband is a type of internet connection that provides high-speed data transmission.

• It is always on and does not require dialing up like traditional dial-up access.

• Broadband can be delivered through various technologies such as DSL, cable, fiber-optic, and satellite.

• It allows for faster download and upload speeds, making it ideal for streaming, gaming, and video confe...read more

DVR stands for Digital Video Recorder and NVR stands for Network Video Recorder. They are both devices used for recording and storing video footage.

• DVR records video footage from analog cameras onto a hard drive.

• NVR records video footage from IP cameras onto a hard drive.

• DVRs are typically used in older surveillance systems, while NVRs are used in modern IP camera systems.

Commands to troubleshoot IPsec 1&2 VPN

• Use 'show crypto isakmp sa' to check the status of ISAKMP SA

• Use 'show crypto ipsec sa' to check the status of IPsec SA

• Use 'debug crypto isakmp' and 'debug crypto ipsec' to enable debugging

• Check the configuration for any errors or mismatches

• Check the firewall and NAT configurations

• Check the routing table for any issues

• Check the logs for any relevant messages

The command used for taking Wireshark logs is 'tcpdump'.

• Wireshark is a network protocol analyzer tool

• Tcpdump is a command-line tool used to capture network traffic

• Tcpdump can be used to capture packets and save them as a file for analysis in Wireshark

• Example command: tcpdump -i eth0 -w capture.pcap

Remote access and IP addressing protocol differences between IPv4 and IPv6

• Remote access allows users to connect to a network from a different location

• IPv4 uses 32-bit addresses while IPv6 uses 128-bit addresses

• IPv4 has a maximum of 4.3 billion unique addresses while IPv6 can support 340 undecillion unique addresses

• IPv6 has built-in security features while IPv4 requires additional security measures

• IPv6 supports multicast communication while IPv4 does not

• IPv6 has simplified hea...read more

Transport layer protocols facilitate the reliable transmission of data between network devices.

• Transmission Control Protocol (TCP) is a connection-oriented protocol that ensures reliable delivery of data.

• User Datagram Protocol (UDP) is a connectionless protocol that provides faster but less reliable transmission.

• Internet Control Message Protocol (ICMP) is used for network error reporting and diagnostic functions.

• Real-Time Transport Protocol (RTP) is commonly used for streamin...read more

Yes, I have knowledge about network switches.

• I am familiar with the basic functions and features of network switches.

• I understand how network switches work to connect devices within a local area network (LAN).

• I have experience configuring and managing network switches.

• I am knowledgeable about different types of network switches, such as managed and unmanaged switches.

• I am aware of common protocols used in network switch operations, such as Spanning Tree Protocol (STP) and VLA...read more

DWDM stands for Dense Wavelength Division Multiplexing. OTN stands for Optical Transport Network.

• DWDM is a technology used in optical communication to increase bandwidth over existing fiber optic networks.

• It allows multiple wavelengths of light to be transmitted over a single fiber optic cable.

• OTN is a digital transport protocol used to transmit data over optical networks.

• It provides features such as error correction, performance monitoring, and network resiliency.

• OTN is used...read more

The hub and spoke model is a transportation or distribution system where a central hub connects to multiple spokes.

• The hub and spoke model is commonly used in logistics and transportation industries.

• In this model, a central hub serves as a consolidation point for goods or services.

• The spokes represent the routes or channels through which goods or services are distributed to various locations.

• The hub and spoke model allows for efficient distribution, as it reduces the need for...read more

VLAN stands for Virtual Local Area Network. It is a logical grouping of devices on a network, allowing for better network management and security.

• VLANs divide a single physical network into multiple virtual networks.

• They help in reducing network congestion and improving network performance.

• VLANs can be configured on switches using commands like 'vlan database', 'vlan ', and 'interface switchport access vlan '.

CRC stands for Cyclic Redundancy Check. It is an error-detecting code used in network communication to ensure data integrity.

• CRC is a mathematical algorithm that generates a fixed-size checksum for a block of data.

• The checksum is appended to the data and is recalculated at the receiving end to check for errors.

• If the calculated checksum doesn't match the received checksum, it indicates that the data has been corrupted during transmission.

• CRC helps in detecting errors caused b...read more

GRR and LRS are statistical methods used in engineering for different purposes.

• GRR stands for Gauge Repeatability and Reproducibility, which measures the variation in measurement systems.

• LRS stands for Linearity, Repeatability, and Stability, which measures the performance of a measurement system over time.

• GRR focuses on the measurement system's ability to provide consistent and repeatable results.

• LRS focuses on the measurement system's linearity, repeatability, and stability...read more

DND stands for 'Do Not Disturb' in networking.

• DND is a feature that can be enabled on a device or network to prevent incoming calls or messages.

• It is commonly used in VoIP systems to prevent incoming calls during important meetings or presentations.

• DND can also be used to block incoming traffic on a network, such as during maintenance or security updates.

Ingress controls the external access to services in a cluster, while service defines a set of pods and how they can be accessed.

• Ingress manages external access to services in a cluster

• Service defines a set of pods and how they can be accessed

• Ingress can provide load balancing, SSL termination, and routing based on hostnames or paths

• Service can be of type ClusterIP, NodePort, LoadBalancer, or ExternalName

To crimp a RJ45 connector, follow these steps:

• Strip about 1 inch of the cable's outer insulation

• Untwist and arrange the wires in the correct order

• Trim the wires to the correct length

• Insert the wires into the connector

• Use a crimping tool to crimp the connector onto the wires

• Repeat the process for the other end of the cable

Fiber cable is a high-speed data transmission cable made of glass or plastic fibers.

• Fiber cable is used for transmitting data over long distances.

• It is made up of thin strands of glass or plastic fibers that are bundled together.

• Fiber cable is faster and more reliable than traditional copper cables.

• It is commonly used in telecommunications, internet, and cable TV networks.

• Fiber cable is also used in medical equipment and industrial applications.

AD stands for Active Directory, which is a directory service used in Windows environments. Range refers to a specific set of values or a span of numbers.

• AD is a centralized database that stores information about network resources, such as users, computers, and groups.

• It provides authentication and authorization services, allowing users to access resources based on their permissions.

• AD uses a hierarchical structure with domains, trees, and forests to organize and manage networ...read more

QPS scheme is a sales incentive program that rewards sales representatives for achieving their sales targets.

• QPS stands for Quarterly Performance Scheme

• It is a sales incentive program that rewards sales representatives for achieving their sales targets

• The rewards can be in the form of cash bonuses, gift vouchers, or other incentives

• The scheme is usually reviewed and renewed every quarter

• It motivates sales representatives to work harder and achieve their targets

• It helps the co...read more

A subnet is a logical subdivision of an IP network. It allows for efficient use of IP addresses and helps in network management.

• Subnets divide a larger network into smaller, more manageable networks.

• They are created by borrowing bits from the host portion of an IP address.

• Subnetting helps in reducing network congestion and improving security.

• Types of subnets include Classful Subnetting, Classless Inter-Domain Routing (CIDR), and Variable Length Subnet Masking (VLSM).

JMS is Java Message Service, a messaging standard that allows Java applications to communicate with each other asynchronously.

• JMS provides a way for applications to send and receive messages in a loosely coupled, reliable, and asynchronous manner.

• PUT and GET are HTTP methods used for RESTful web services, not JMS.

• In JMS, messages are sent using the 'send' method and received using the 'receive' method.

• JMS supports two types of messaging: point-to-point and publish-subscribe.

• J...read more

A server is a computer system that provides services to other computers or devices on a network. Hardware refers to the physical components of a computer system. Networking is the process of connecting multiple devices together to share resources.

• A server is designed to provide specific services to other devices on a network, such as file sharing, email, or web hosting.

• Hardware includes components such as the CPU, RAM, hard drive, and motherboard.

• Networking involves connectin...read more

Monitoring is the process of observing and checking the progress or quality of something.

• Monitoring involves regularly checking and observing a system, process, or activity to ensure it is functioning correctly.

• It helps in identifying any issues or deviations from the expected performance.

• Monitoring can be done through various methods such as visual inspections, data analysis, or using specialized tools.

• Examples of monitoring include tracking website traffic, monitoring patie...read more

Baud rate is the rate at which data is transmitted over a communication channel.

• Baud rate is measured in bits per second (bps).

• Higher baud rates allow for faster data transmission.

• Baud rate must be set the same on both ends of the communication channel.

• Incorrect baud rate settings can result in data corruption or loss.

• Examples of communication channels that use baud rate include UART, SPI, and I2C.

A network is a group of interconnected devices that communicate with each other to share resources and information.

• Basic things used in networking include routers, switches, hubs, and cables.

• Network protocols such as TCP/IP, DNS, and DHCP are also essential.

• Network security measures like firewalls and VPNs are important to protect against unauthorized access.

• Monitoring tools like Wireshark and Nagios are used to troubleshoot network issues.

• Networking concepts like subnetting,...read more

To build a server with AD, install Windows Server OS, configure network settings, install AD DS role, and create domain.

• Install Windows Server OS on the server machine

• Configure network settings including IP address, subnet mask, and default gateway

• Install Active Directory Domain Services (AD DS) role on the server

• Configure AD DS by creating a new domain or joining an existing domain

• Configure DNS settings for the domain

• Create user accounts and groups in AD

• Configure security se...read more

RF stands for Radio Frequency. It refers to the range of electromagnetic frequencies used for wireless communication.

• RF is used in various telecommunication systems, including mobile phones, Wi-Fi, and satellite communication.

• It is a form of wireless communication that uses radio waves to transmit and receive data.

• RF signals can be used for voice, video, and data transmission.

• Examples of RF devices include antennas, transmitters, receivers, and routers.

A domain is a network of computers and devices that are managed as a single entity.

• A domain is a collection of computers and devices that share a common security and administration policy.

• A domain controller is a server that manages the security and authentication of users and computers in the domain.

• To add a system to a domain, the system must be configured to use the domain controller as its primary DNS server and then joined to the domain using valid credentials.

• Once a sys...read more

Monitoring a remote server involves setting up monitoring tools, configuring alerts, and regularly checking performance metrics.

• Use monitoring tools like Nagios, Zabbix, or Prometheus to track server performance.

• Set up alerts for key metrics such as CPU usage, memory usage, disk space, and network traffic.

• Regularly check logs for any errors or warnings that may indicate issues on the remote server.

• Implement automated monitoring scripts to periodically check server health and ...read more

Ingress controller is a Kubernetes resource that manages external access to services within a cluster.

• Ingress controller acts as a traffic manager, routing incoming traffic to the appropriate services based on rules defined in the Ingress resource.

• It allows for the configuration of HTTP and HTTPS routing, load balancing, SSL termination, and more.

• Popular Ingress controllers include Nginx Ingress Controller, Traefik, and HAProxy.

• Ingress controllers can be used to expose multip...read more

Various network protocols include TCP/IP, HTTP, FTP, SMTP, DNS, DHCP, and more.

• TCP/IP is the most commonly used protocol for internet communication

• HTTP is used for web browsing and transferring data between web servers and clients

• FTP is used for file transfer between computers

• SMTP is used for email communication

• DNS is used for domain name resolution

• DHCP is used for automatic IP address assignment

• Other protocols include SSH, Telnet, SNMP, and more

VxLAN stands for Virtual Extensible LAN, a technology used to extend Layer 2 networks over Layer 3 networks.

• VxLAN encapsulates Layer 2 Ethernet frames within Layer 3 UDP packets for transmission over IP networks.

• It uses a 24-bit identifier called the VxLAN Network Identifier (VNI) to distinguish between different virtual networks.

• VxLAN allows for up to 16 million virtual networks to coexist in the same administrative domain.

• It helps in creating large-scale multi-tenant cloud ...read more

FTP is a protocol used for transferring files over the internet.

• FTP stands for File Transfer Protocol.

• It is used to transfer files between a client and a server over the internet.

• FTP uses two channels, one for data transfer and the other for control information.

• FTP can be used with a username and password for authentication.

• Examples of FTP clients include FileZilla, WinSCP, and Cyberduck.

A service is a recurring activity provided to a customer, while a request is a one-time demand made by a customer.

• Service is ongoing, request is one-time

• Service is provided regularly, request is made as needed

• Service is often part of a contract, request is not

• Examples of services: monthly maintenance, software updates

• Examples of requests: technical support, equipment repair

SSH is a secure protocol used for remote login and file transfer, while Telnet is an insecure protocol used for remote login.

• SSH encrypts the data transmitted over the network, while Telnet sends data in plain text.

• SSH uses public-key cryptography for authentication, while Telnet uses username and password.

• SSH provides secure remote access to servers, while Telnet lacks security measures.

• SSH is the recommended protocol for remote administration, while Telnet is outdated and i...read more

There are three types of alignment in mechanical maintenance: shaft alignment, belt alignment, and coupling alignment.

• Shaft alignment involves aligning the rotational axes of two shafts in order to minimize vibration and wear.

• Belt alignment ensures that the belts are properly aligned on pulleys to prevent slippage and maximize power transmission.

• Coupling alignment focuses on aligning the coupling halves to maintain proper torque transmission and prevent misalignment-related i...read more

I will see the status of the devices and their connection status to the MQTT broker.

• Check the connection status of each device to the MQTT broker

• Monitor the data flow between the devices and the MQTT broker

• Identify any errors or issues in the connection process

• Ensure that all devices are successfully connected to the MQTT broker

Domain is a logical group of computers while forest is a collection of domains.

• Domain is a security boundary within which users, computers, and other resources are managed.

• Forest is a collection of one or more domains that share a common schema, configuration, and global catalog.

• Domains can be organized into a hierarchy, while forests cannot.

• Domains can have different security policies, while forests have a common security policy.

• Example: A company may have multiple domains f...read more

I would troubleshoot the error by checking the WSUS logs and database, and then take appropriate action.

• Check the WSUS logs to identify the error

• Check the WSUS database for any issues

• Restart the WSUS service if necessary

• Run the WSUS cleanup wizard to remove any unnecessary updates

• Manually synchronize WSUS with Microsoft Update

• If all else fails, reinstall WSUS

ADDS stands for Active Directory Domain Services.

• ADDS is a Microsoft service that provides centralized authentication and authorization for Windows-based computers.

• It allows administrators to manage users, computers, and other resources in a network environment.

• ADDS is a key component of Microsoft's Active Directory technology.

• It is used to create and manage domains, domain controllers, and other directory objects.

• ADDS also provides features such as group policy management, L...read more

To configure Outlook in Exchange Server, follow these steps:

• Open Outlook and click on File

• Click on Add Account

• Enter your email address and click on Connect

• Enter your password and click on OK

• Outlook will automatically configure the settings for Exchange Server

RSTP and STP are network protocols used to prevent loops in Ethernet networks.

• STP stands for Spanning Tree Protocol and is the older of the two protocols.

• RSTP stands for Rapid Spanning Tree Protocol and is an updated version of STP.

• Both protocols work by creating a loop-free logical topology of the network.

• STP and RSTP determine the best path for data to travel through the network.

• RSTP is faster than STP in detecting and recovering from network failures.

Packet flow is the movement of data packets from one network device to another.

• Packet flow starts when a user sends data packets to a network device.

• The device then checks the destination address and forwards the packet to the next device in the path.

• This process continues until the packet reaches its destination user.

• Packet flow can be affected by network congestion, routing issues, and other factors.

• Protocols like TCP and UDP help ensure reliable packet delivery.

• Packet flow...read more

A firewall can be used to manage network traffic and ensure smooth operation.

• Define clear security policies and rules for the firewall

• Regularly update and maintain the firewall software

• Monitor network traffic and adjust firewall settings as needed

• Implement intrusion detection and prevention systems

• Train employees on safe browsing habits and network security

• Use VPNs to secure remote access to the network

DHCP is a network protocol that automatically assigns IP addresses to devices on a network. DOMAIN Name is a unique name that identifies a website or network.

• DHCP stands for Dynamic Host Configuration Protocol

• It allows devices to obtain IP addresses, subnet masks, and other network configuration settings automatically

• DHCP servers manage a pool of available IP addresses and lease them to devices on the network

• DOMAIN Name is a human-readable name that corresponds to the IP addr...read more

DNS server is a computer server that contains a database of public IP addresses and their associated hostnames.

• DNS stands for Domain Name System

• It translates domain names into IP addresses

• DNS servers can be authoritative or recursive

• DC stands for Domain Controller

• It is a server that authenticates users and computers in a Windows domain network

• It manages security policies and distributes software updates

IP address classes are a way of categorizing IP addresses based on their first octet.

• There are five classes: A, B, C, D, and E.

• Class A addresses start with a number between 1 and 126.

• Class B addresses start with a number between 128 and 191.

• Class C addresses start with a number between 192 and 223.

• Class D addresses are used for multicasting.

• Class E addresses are reserved for future use.

• The class of an IP address determines the range of IP addresses that can be assigned within...read more