100+ NOC Engineer Interview Questions and Answers

OSPF (Open Shortest Path First) is a routing protocol used to determine the best path for data packets in a network.

• OSPF is used to efficiently route traffic in large networks by calculating the shortest path between routers.

• It is a link-state routing protocol that uses Dijkstra's algorithm to determine the best path.

• OSPF is preferred over other routing protocols like RIP due to its faster convergence time and scalability.

• It supports VLSM (Variable Length Subnet Masking) and ...read more

A virtual private network (VPN) extends a private network across a public network, allowing users to send and receive data securely.

• Encrypts data to ensure privacy and security

• Allows users to access a private network remotely

• Masks IP address to protect user's identity

• Commonly used for remote work, accessing geo-blocked content, and enhancing online security

• Examples include NordVPN, ExpressVPN, and CyberGhost

To create users in AD, use Active Directory Users and Computers console or PowerShell cmdlets.

• Open Active Directory Users and Computers console

• Right-click on the domain and select 'New' and then 'User'

• Fill in the required user information and click 'Next' until the user is created

• Alternatively, use PowerShell cmdlets like New-ADUser to create users programmatically

Network architecture refers to the design and layout of a computer network.

• It includes the physical components of the network such as routers, switches, and cables.

• It also includes the logical components such as protocols and network topologies.

• The architecture should be designed to meet the needs of the organization and provide efficient and secure communication.

• Examples of network architectures include client-server, peer-to-peer, and cloud-based.

• Network architecture can be...read more

SSH is a secure protocol for remote access while Telnet is an unsecured protocol.

• SSH encrypts data while Telnet sends data in plain text.

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

• SSH is more secure and recommended over Telnet.

• SSH uses port 22 while Telnet uses port 23.

• SSH is used for remote access to servers while Telnet is mostly used for testing network connectivity.

RSSI stands for Received Signal Strength Indicator and is a measurement of the power level being received by a device.

• RSSI is a value that indicates the strength of the signal being received by a device.

• RF devices work on the best RSSI by constantly monitoring and adjusting their connection to maintain the strongest signal.

• Devices can switch between different access points or channels to find the best RSSI for optimal performance.

• Examples of RF devices include Wi-Fi routers, ...read more

Switch is a network device that connects devices together in a local area network. Router is a network device that connects multiple networks together. OSI model is a conceptual model that describes how data is transmitted over a network.

• Switch operates at layer 2 of the OSI model and uses MAC addresses to forward data between devices.

• Router operates at layer 3 of the OSI model and uses IP addresses to route data between networks.

• OSI model has 7 layers: Physical, Data Link, N...read more

Routing protocol is a set of rules used by routers to determine the best path for data packets to reach their destination.

• Routing protocols help routers communicate with each other to share information about network topology.

• They use algorithms to calculate the best path for data packets based on factors like hop count, bandwidth, and delay.

• Examples of routing protocols include RIP, OSPF, EIGRP, and BGP.

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

Configuring Outlook involves setting up email accounts, server settings, and security options.

• Open Outlook and click on File

• Click on Add Account and enter your email address

• Enter your password and follow the prompts to complete setup

• Configure server settings such as incoming and outgoing mail servers

• Set up security options such as encryption and authentication

• Test the account to ensure it is working properly

RAN stands for Radio Access Network, VLAN is Virtual Local Area Network, 4G and 5G are mobile network technologies, and incident management involves handling and resolving network issues.

• RAN (Radio Access Network) is a part of a mobile telecommunication system that connects individual devices to other parts of a network through radio connections.

• VLAN (Virtual Local Area Network) is a technology that allows multiple networks to coexist on the same physical infrastructure, prov...read more

Transmission lines are used to transmit electrical power or signals from one point to another.

• Transmission lines are made of conductive materials such as copper or aluminum.

• They are used to transmit power or signals over long distances.

• Transmission lines can be overhead or underground.

• The type of transmission line used depends on the amount of power or signal being transmitted.

• Examples of transmission lines include power lines, telephone lines, and fiber optic cables.

ARP is a protocol used to map an IP address to a physical MAC address on a local network.

• ARP stands for Address Resolution Protocol.

• It operates at the Data Link Layer of the OSI model.

• ARP is used to resolve IP addresses to MAC addresses.

• It is essential for communication between devices on the same network.

• ARP requests are broadcasted to all devices on the network.

• Example: When a computer wants to send data to another device, it uses ARP to find the MAC address of the destinat...read more

Modulation is the process of varying a signal's characteristics to transmit information. TCP/IP is a protocol used for communication between devices. Guard band is a frequency band used to separate two channels.

• Modulation is used in radio communication to transmit information by varying the amplitude, frequency, or phase of a carrier wave.

• TCP/IP is a set of protocols used for communication between devices on a network. It includes protocols for data transmission, routing, and...read more

ISIS and MDLS are protocols used in networking for routing and network management.

• ISIS (Intermediate System to Intermediate System) is a routing protocol used to exchange routing information between network devices.

• MDLS (Management Data Input/Output Link Service) is a protocol used for network management tasks such as monitoring and configuration.

• ISIS is commonly used in large enterprise networks and internet service provider networks.

• MDLS helps network administrators to mana...read more

I communicate with clients through clear and concise emails, phone calls, and in-person meetings.

• Regularly update clients on the status of their network issues

• Provide detailed explanations of technical issues in non-technical terms

• Listen actively to client concerns and address them promptly

• Offer solutions and recommendations for improving network performance

• Schedule regular meetings to discuss ongoing projects and future plans

Routing protocols are sets of rules that determine how routers communicate with each other to forward data packets across networks.

• Routing protocols are used to exchange routing information between routers.

• They help routers to build and maintain routing tables.

• There are two types of routing protocols: interior gateway protocols (IGPs) and exterior gateway protocols (EGPs).

• Examples of IGPs include OSPF and EIGRP, while BGP is an example of an EGP.

VLAN stands for Virtual Local Area Network. VLAN port modes determine how a switch port behaves in relation to VLANs.

• VLAN is a logical grouping of devices on the same network segment

• VLAN port modes include access, trunk, and hybrid

• Access mode assigns a port to a specific VLAN

• Trunk mode allows the port to carry traffic for multiple VLANs

• Hybrid mode allows the port to carry both tagged and untagged traffic

SDH stands for Synchronous Digital Hierarchy, a standardized technology for synchronous data transmission over fiber optic networks. Receiving sensitivity refers to the minimum signal strength required for a receiver to detect and decode incoming data.

• SDH is a technology used for transmitting data over fiber optic networks in a synchronous manner.

• It provides a standardized way of organizing and multiplexing multiple digital signals into a single high-speed data stream.

• Receivi...read more

TCP models refer to the different layers of the TCP/IP protocol stack. Management VLANs are used to manage network devices.

• TCP models consist of four layers: application, transport, internet, and network access

• Management VLANs are used to separate management traffic from regular network traffic

• They allow for easier management of network devices such as switches and routers

• Management VLANs can be configured on a per-port basis or for the entire network

• Examples of management VL...read more

2G, 3G, and 4G are different generations of mobile network technology.

• 2G stands for second generation and is based on digital technology. It allows for basic voice and text communication.

• 3G stands for third generation and introduced mobile data and internet connectivity.

• 4G stands for fourth generation and offers faster internet speeds and improved data transfer rates.

• Examples of 2G networks include GSM and CDMA. Examples of 3G networks include UMTS and HSPA. Examples of 4G ne...read more

Hot Standby Routing Protocol (HSRP) is a Cisco proprietary protocol that provides redundancy for IP networks.

• HSRP allows multiple routers to work together in a group, with one router acting as the active router and others as standby routers.

• The active router handles the traffic while the standby routers are ready to take over in case of failure.

• HSRP uses a virtual IP address and a virtual MAC address to provide seamless failover.

• It operates at the network layer and provides h...read more

An operating system (OS) is a software that manages computer hardware and software resources and provides common services for computer programs.

• OS acts as an interface between the user and the computer hardware.

• It manages the computer's memory and processes.

• Examples of OS include Windows, macOS, Linux, Android, and iOS.

Networking refers to the practice of connecting devices together to share resources and communicate with each other.

• Networking involves the use of protocols and technologies such as TCP/IP, DNS, DHCP, and VLANs.

• Common networking devices include routers, switches, firewalls, and access points.

• Networking can be used for a variety of purposes, such as sharing files and printers, accessing the internet, and enabling communication between devices.

• Networking can be wired or wireles...read more

BGP attributes are used to influence the path selection process in BGP routing.

• BGP attributes include AS_PATH, NEXT_HOP, LOCAL_PREF, etc.

• AS_PATH is a list of AS numbers that the route has traversed.

• NEXT_HOP is the IP address to reach the next hop towards the destination.

• LOCAL_PREF is used to influence outbound traffic.

• MED (Multi-Exit Discriminator) is used to influence inbound traffic.

• Weight is a Cisco-specific attribute used for path selection within the same AS.

• Communities ...read more

Covid 19 has had a significant impact on India.

• India has reported a high number of Covid cases and deaths.

• The pandemic has affected the economy, leading to job losses and reduced income.

• The healthcare system has been overwhelmed, with shortages of hospital beds, oxygen, and medicines.

• The government has implemented lockdowns and other measures to control the spread of the virus.

• Vaccination efforts have been ramped up, but there are still challenges in reaching all segments of ...read more

RAID stands for Redundant Array of Independent Disks. It is a data storage technology that combines multiple physical disk drives into a single logical unit.

• RAID provides improved performance, fault tolerance, and data protection.

• There are different RAID levels, each with its own advantages and disadvantages.

• RAID 0 offers improved performance but no redundancy, while RAID 1 provides redundancy but no performance improvement.

• RAID 5 and RAID 6 offer both performance improvement...read more

Protecting the 11kv transformer involves implementing proper maintenance, monitoring, and security measures.

• Regular maintenance checks to ensure proper functioning

• Installing surge protection devices to prevent damage from power surges

• Implementing temperature monitoring to prevent overheating

• Securing the transformer area to prevent unauthorized access

• Using proper grounding techniques to prevent electrical faults

Round robin algorithm is a scheduling algorithm that assigns equal time slices to each process in a circular manner.

• Assigns time slices to processes in a circular manner

• Each process gets an equal amount of time before moving to the next process

• Helps in achieving fairness in process scheduling

• Used in network load balancing, CPU scheduling, and disk scheduling

BGP (Border Gateway Protocol) is a standardized exterior gateway protocol used to exchange routing information between different autonomous systems on the internet.

• BGP has four main stages: Idle, Connect, OpenSent, and Established.

• In the Idle stage, the BGP process is not running.

• In the Connect stage, a TCP connection is established with the neighbor.

• In the OpenSent stage, BGP parameters are exchanged.

• In the Established stage, the BGP peers are fully synchronized and can exch...read more

EtherChannel is a technology that allows multiple physical links to be combined into a single logical link.

• EtherChannel provides increased bandwidth and redundancy.

• It is commonly used in network switches to aggregate multiple links between switches.

• By bundling multiple links, EtherChannel enhances performance and load balancing.

• It also provides link redundancy, ensuring network availability in case of link failures.

• EtherChannel can be configured using various protocols such a...read more

WDS is a Windows Deployment Services used for network-based installation of Windows OS. MDT is a Microsoft Deployment Toolkit used for customizing and automating Windows OS deployment.

• WDS is used for network-based installation of Windows OS

• MDT is used for customizing and automating Windows OS deployment

• WDS is a component of Windows Server

• MDT is a standalone tool that can be used with WDS or other deployment tools

CDM stands for Configuration and Data Management. It is a process of managing and maintaining the configuration and data of a system.

• CDM involves tracking and documenting changes made to a system's configuration and data.

• It ensures that all changes are properly authorized and documented.

• CDM helps in maintaining the integrity and consistency of a system's configuration and data.

• Examples of CDM tools include Git, Ansible, and Puppet.

CDMA is a wireless communication technology that allows multiple users to share the same frequency band simultaneously.

• CDMA stands for Code Division Multiple Access.

• It uses spread spectrum technology to allow multiple users to transmit data simultaneously.

• Each user is assigned a unique code to differentiate their signal from others.

• Examples of CDMA networks include Verizon and Sprint in the US.

• HandShaking is a process in telecom where two devices exchange information to estab...read more

Routing protocols are used to exchange routing information between routers to determine the best path for data transmission.

• Routing protocols are used to facilitate communication between routers in a network.

• They determine the best path for data transmission based on various metrics such as hop count, bandwidth, and delay.

• Examples of routing protocols include OSPF, BGP, and EIGRP.

• Routing protocols can be classified as either distance-vector or link-state protocols.

• Distance-ve...read more

PDN down in EPDG refers to the process of deactivating a Packet Data Network (PDN) connection in an Evolved Packet Data Gateway (EPDG).

• PDN down in EPDG is typically performed to release network resources and terminate a user's data session.

• This can be achieved by sending a PDN disconnect request to the EPDG.

• The EPDG will then release the resources associated with the PDN connection and notify the user equipment (UE) about the disconnection.

• Examples of triggering PDN down in E...read more

Hard reset in BGP involves restarting the BGP process and clearing all BGP routing information, while soft reset involves refreshing BGP routes without restarting the process.

• Hard reset involves restarting the BGP process and clearing all BGP routing information

• Soft reset involves refreshing BGP routes without restarting the BGP process

• Hard reset is more disruptive as it clears all routing information, while soft reset is less disruptive

Yes, I have a strong Linux background.

• Proficient in Linux command line interface

• Experience with Linux server administration

• Familiarity with Linux networking and security

• Comfortable with shell scripting and automation

• Examples: Configuring Apache web server, setting up SSH access, troubleshooting network connectivity issues

OST and PST are file extensions used by Microsoft Outlook to store email data.

• OST stands for Offline Storage Table and is used for storing email data when Outlook is in offline mode.

• PST stands for Personal Storage Table and is used for storing email data on the user's computer.

• OST files are created automatically when Outlook is configured to use Cached Exchange Mode.

• PST files can be created manually by the user to store email data locally.

• Both OST and PST files can be importe...read more

WDM stands for Wavelength Division Multiplexing, a technology that allows multiple data streams to be transmitted simultaneously over a single optical fiber by using different wavelengths of light.

• WDM is used in fiber optic communication systems to increase the capacity of the network.

• It allows for the transmission of multiple signals over a single fiber by using different wavelengths of light.

• There are two types of WDM: coarse wavelength division multiplexing (CWDM) and dens...read more

Networking is the practice of connecting computers and other devices to share resources and information.

• Networking involves the use of hardware such as routers, switches, and cables to create a network.

• It also includes the use of software protocols like TCP/IP to facilitate communication between devices.

• Networking allows devices to share resources such as files, printers, and internet connections.

• Examples of networking technologies include Ethernet, Wi-Fi, and VPNs.

OSI reference model is a conceptual model that characterizes and standardizes the communication functions of a telecommunication or computing system.

• OSI stands for Open Systems Interconnection.

• It has 7 layers: Physical, Data Link, Network, Transport, Session, Presentation, and Application.

• Each layer has a specific function and communicates with the adjacent layers.

• It helps in understanding how data is transmitted over a network.

• Example: When you access a website, your compute...read more

I am familiar with monitoring tools such as Nagios, Zabbix, SolarWinds, and PRTG.

• Nagios

• Zabbix

• SolarWinds

• PRTG

OSPF (Open Shortest Path First) is a routing protocol used to find the best path for data packets in a network.

• OSPF is a link-state routing protocol that uses Dijkstra's algorithm to calculate the shortest path to each network.

• It operates within an autonomous system (AS) and exchanges routing information using link-state advertisements (LSAs).

• OSPF routers build a topology map of the network and use this information to determine the best path to each destination.

• It supports VL...read more

EIGRP and OSPF are routing protocols used in computer networks.

• EIGRP (Enhanced Interior Gateway Routing Protocol) messages include Hello, Update, Query, Reply, and Acknowledgment.

• OSPF (Open Shortest Path First) messages include Hello, Database Description, Link State Request, Link State Update, and Link State Acknowledgment.

HDD is a traditional spinning hard drive, while SSD is a newer, faster type of drive that uses flash memory.

• HDD uses spinning disks to read/write data, while SSD uses flash memory chips.

• SSD is faster and more reliable than HDD.

• SSD is more expensive than HDD.

• SSD consumes less power than HDD.

• SSD has no moving parts, making it less prone to physical damage.

• HDD has larger storage capacity than SSD.

• SSD is commonly used in laptops and tablets, while HDD is used in desktop computers...read more

Node analysis monitoring involves tracking and analyzing the performance and health of network nodes.

• Use network monitoring tools to collect data on node performance

• Monitor key metrics such as CPU usage, memory utilization, and network traffic

• Set up alerts and notifications for abnormal behavior or performance degradation

• Perform regular analysis of collected data to identify trends and potential issues

• Use visualization tools to create dashboards and reports for easy analysis

• I...read more