60+ L2 Network Engineer Interview Questions and Answers

The best link of OMP route depends on the specific needs and requirements of the network.

• Internet may be a better option for cost-effectiveness and flexibility, but MPLS may offer better reliability and security.

• Consider factors such as bandwidth, latency, traffic volume, and application requirements.

• Evaluate the pros and cons of each option before making a decision.

• For example, if the network requires low latency and high reliability, MPLS may be the better choice.

• On the oth...read more

BGP is used for routing between different autonomous systems, while IBGP is used for routing within the same autonomous system.

• BGP (Border Gateway Protocol) is an exterior gateway protocol used for routing between different autonomous systems.

• IBGP (Internal Border Gateway Protocol) is used for routing within the same autonomous system.

• BGP is used to exchange routing information between different autonomous systems (ASes) on the internet.

• IBGP is used to distribute routing info...read more

Policy is a set of rules or guidelines that dictate how a network should be managed and used.

• Identify the purpose of the policy

• Define the scope of the policy

• Determine the target audience

• Create the policy document

• Communicate the policy to all stakeholders

• Enforce the policy and regularly review and update it

No, SVIs cannot be created in L2 switches.

• SVI stands for Switched Virtual Interface.

• It is a virtual interface that represents a VLAN on a Layer 3 switch.

• L2 switches operate at Layer 2 of the OSI model and do not support routing or Layer 3 functionality.

• SVIs are used for routing between VLANs, which is a Layer 3 function.

• L2 switches can only create VLANs and assign ports to them for Layer 2 switching.

• To enable Layer 3 functionality, a Layer 3 switch or a router is required.

TLOC in Viptela SDWAN stands for Transport Locator and is used to identify the physical or virtual location of a device in the network.

• TLOC is a unique identifier assigned to each device in the SDWAN network.

• It helps in determining the optimal path for traffic routing.

• TLOCs can be based on various parameters such as interface, IP address, or VPN.

• They are used to define the connectivity between different sites in the network.

• TLOCs enable efficient traffic steering and load bal...read more

L2 switches operate at the data link layer and L3 switches operate at the network layer.

• L2 switches forward traffic based on MAC addresses while L3 switches forward traffic based on IP addresses.

• L2 switches are simpler and less expensive than L3 switches.

• L3 switches can perform routing functions and support multiple VLANs while L2 switches cannot.

• L3 switches are used in larger networks where routing and VLANs are necessary.

• Examples of L2 switches include Cisco Catalyst 2960 a...read more

BGP and OSPF are both routing protocols, but BGP is used for inter-domain routing while OSPF is used for intra-domain routing.

• BGP is important in respect of OSPF because it allows for communication between different autonomous systems (AS)

• BGP is used to exchange routing information between different AS, while OSPF is used within a single AS

• BGP is used to determine the best path for traffic to take between different AS, while OSPF is used to determine the best path within a si...read more

The basic steps of network troubleshooting involve identifying the problem, gathering information, isolating the issue, testing solutions, and implementing fixes.

• Identify the problem by gathering information from the user or monitoring tools

• Isolate the issue by checking connectivity, configurations, and logs

• Test potential solutions by implementing changes or using diagnostic tools

• Implement fixes by applying changes to the network devices or configurations

• Verify the resolution...read more

Use pre-staged image and fast transfer methods to achieve IOS upgrade within 10 minutes.

• Pre-stage the image on the device before the upgrade window

• Use fast transfer methods like TFTP or FTP to transfer the image quickly

• Ensure all necessary configurations are saved and backed up before the upgrade

• Have a rollback plan in case of any issues during the upgrade

STP stands for Spanning Tree Protocol. Port Fast is a feature in STP that allows a port to bypass the listening and learning states.

• STP is a protocol used to prevent loops in a network by blocking redundant paths

• It works by electing a root bridge and calculating the shortest path to it

• Port Fast is a feature that allows a port to immediately transition to forwarding state, bypassing the listening and learning states

• It is used on ports that are not connected to other switches t...read more

Switch, router, and modem are networking devices used to connect devices and facilitate communication over a network.

• Switch: Connects devices within a local area network (LAN) and forwards data packets between them. Example: Cisco Catalyst switch.

• Router: Connects multiple networks together and routes data packets between them. Example: Cisco ISR router.

• Modem: Converts digital data from a computer into analog signals for transmission over telephone lines (DSL modem) or vice ve...read more

Yes, I have experience with monitoring tools.

• I have experience with tools such as SolarWinds, Nagios, and PRTG.

• I am familiar with setting up alerts and notifications based on specific thresholds.

• I have used monitoring tools to troubleshoot network issues and identify performance bottlenecks.

• I am comfortable creating custom dashboards and reports to provide visibility into network health.

• I have experience with both on-premise and cloud-based monitoring solutions.

BGP, OSPF, VLAN, trunking, router integration, and troubleshooting processes are key aspects of network engineering.

• BGP (Border Gateway Protocol) is used to exchange routing information between different autonomous systems.

• OSPF (Open Shortest Path First) is a routing protocol used within a single autonomous system.

• VLAN (Virtual Local Area Network) is used to segment a network into multiple logical networks.

• Trunking is the process of carrying multiple VLANs over a single netwo...read more

Explanation of OSPF, STP types and VLAN creation.

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

• STP (Spanning Tree Protocol) prevents loops in a network by blocking redundant paths.

• STP types include PVST (Per-VLAN Spanning Tree), RPVST+ (Rapid PVST+), and MSTP (Multiple Spanning Tree Protocol).

• VLANs (Virtual Local Area Networks) are created to segment a network into smaller broadcast domains and improve network performance....read more

To add two ISP links in one OSPF router, we need to create two virtual links.

• Create two virtual links with the respective ISP router IDs

• Assign the virtual links to the OSPF process

• Configure the virtual links with the appropriate IP addresses and subnet masks

• Ensure that the virtual links are enabled

• Verify the OSPF neighborship with the ISP routers

STP stands for Spanning Tree Protocol. It is a network protocol that prevents loops in a network topology.

• STP is used to prevent network loops by creating a logical tree structure of the network.

• It works by selecting a root bridge and disabling redundant paths to prevent loops.

• STP uses Bridge Protocol Data Units (BPDUs) to communicate with other switches and determine the best path to the root bridge.

• STP has several variants, including Rapid Spanning Tree Protocol (RSTP) and ...read more

VKAN stack and OSPF L2 L1 switch router are networking protocols covered in CCNA course.

• VKAN stack is a proprietary protocol used for virtualization in data centers.

• OSPF (Open Shortest Path First) is a routing protocol used for efficient communication between routers.

• L2 and L1 refer to the layers in the OSI model, with L2 being the data link layer and L1 being the physical layer.

• Switches and routers are networking devices used for forwarding data packets.

• CCNA (Cisco Certified...read more

Routers operate at Layer 3 of the OSI model and make decisions based on IP addresses, while switches operate at Layer 2 and make decisions based on MAC addresses.

• Routers operate at Layer 3 of the OSI model, while switches operate at Layer 2.

• Routers make decisions based on IP addresses, while switches make decisions based on MAC addresses.

• Routers connect different networks together, while switches connect devices within the same network.

• Routers use routing tables to determine ...read more

LAN stands for Local Area Network, which connects devices within a limited area. WAN stands for Wide Area Network, which connects devices over a large geographical area.

• LAN is typically used in homes, schools, or small businesses.

• LAN has high data transfer speeds and low latency.

• Examples of LAN technologies include Ethernet and Wi-Fi.

• WAN connects devices across cities, countries, or continents.

• WAN has slower data transfer speeds compared to LAN due to longer distances.

• Example...read more

OSPF DR and BDR are routers elected to manage communication within a multi-access network.

• DR stands for Designated Router and BDR stands for Backup Designated Router.

• They are elected by OSPF routers on a multi-access network to manage communication.

• DR and BDR are responsible for maintaining the topology database and forwarding updates to other routers.

• They reduce the amount of OSPF traffic on the network by acting as a central point of contact.

• If the DR fails, the BDR takes o...read more

I prioritize tasks based on urgency and importance, use time management techniques, and communicate effectively with team members.

• Prioritize tasks based on urgency and importance

• Use time management techniques such as creating to-do lists and setting deadlines

• Communicate effectively with team members to ensure tasks are completed efficiently

• Stay organized and focused to avoid feeling overwhelmed by multiple tasks

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

• Networks can be wired or wireless

• They can be local (LAN) or wide area (WAN)

• They use protocols such as TCP/IP to facilitate communication

• Examples include the internet, corporate networks, and home networks

A switch is a networking device that operates at Layer 2 of the OSI model, handling data at the data link layer.

• Switches forward data based on MAC addresses

• Operate at Layer 2 of the OSI model

• Used to create LANs and connect devices within a network

• Helps reduce network congestion by only sending data to the intended recipient

Trunk is a link between switches carrying multiple VLANs. VLAN configuration is assigning ports to specific VLANs.

• Trunk is used to carry multiple VLANs over a single link between switches

• VLAN configuration is used to group ports into separate broadcast domains

• VLANs can be used to segregate traffic, improve security, and optimize network performance

• Examples of VLAN configuration include assigning ports to specific VLANs based on department or function

• Trunk configuration involv...read more

Planning, designing, and implementing best solutions involves identifying the problem, researching options, and executing the chosen solution.

• Identify the problem or need

• Research and evaluate potential solutions

• Select the best solution based on cost, feasibility, and effectiveness

• Implement the chosen solution

• Monitor and evaluate the solution's effectiveness over time

Routing is the process of selecting the best path for network traffic to reach its destination.

• Routing helps in directing network traffic efficiently

• It determines the best path for data packets to travel from source to destination

• Routing protocols like OSPF, BGP, and EIGRP are used to exchange routing information

• Routing tables are used to store information about network paths

• Dynamic routing adjusts to network changes automatically

In the OSI model, each layer has specific functions and responsibilities in the communication process.

• The OSI model consists of 7 layers, each with its own specific functions and responsibilities.

• Each layer communicates with the adjacent layers to ensure data is properly transmitted.

• For example, in the OSI model, Layer 1 (Physical layer) deals with the physical connection between devices, while Layer 2 (Data Link layer) handles data framing and error detection.

A firewall is a network security device that monitors and controls incoming and outgoing network traffic based on predetermined security rules.

• Firewall acts as a barrier between a trusted internal network and an untrusted external network.

• It filters network traffic based on IP addresses, ports, protocols, and other criteria.

• Firewalls can be hardware-based or software-based.

• They can be configured to allow or block specific types of traffic.

• Examples of firewalls include Cisco A...read more

A router is a networking device that forwards data packets between computer networks.

• Routers operate at the network layer of the OSI model.

• They use routing tables to determine the best path for data to travel.

• Routers can connect different types of networks, such as LANs and WANs.

• Examples of routers include Cisco, Juniper, and TP-Link.

• Routers can provide security features such as firewalls and VPNs.

To troubleshoot IPSec VPN issues, start by checking the configuration, verifying connectivity, and analyzing logs.

• Verify the IPSec configuration on both ends to ensure they match

• Check for any network connectivity issues between the VPN peers

• Analyze the VPN logs for any error messages or warnings

• Ensure that the correct encryption and authentication settings are being used

• Check for any firewall rules blocking the VPN traffic

Firewall generations refer to the evolution of firewall technology and their roles in network security.

• First generation firewalls - packet filtering based on IP addresses and ports

• Second generation firewalls - stateful inspection and improved security features

• Third generation firewalls - application layer filtering and deep packet inspection

• Fourth generation firewalls - next-generation firewalls with advanced threat protection capabilities

• Each generation builds upon the previ...read more

Comprehensive call flow refers to the detailed sequence of events that occur during a phone call or communication session.

• It includes the initiation of the call, routing through various network elements, and termination of the call.

• Comprehensive call flow diagrams often illustrate the flow of signaling and media traffic between different network components.

• Understanding call flows is essential for troubleshooting network issues and optimizing call quality.

• Examples of call flo...read more

IPS stands for Intrusion Prevention System. It is a network security technology that monitors network traffic to detect and prevent malicious activities.

• IPS is a network security technology that monitors network traffic in real-time.

• It can detect and prevent malicious activities such as hacking attempts, malware infections, and denial-of-service attacks.

• IPS works by analyzing network packets, comparing them to a database of known threats, and taking action to block or allow t...read more

EIGRP Authentication is a security feature that ensures only authorized routers can participate in EIGRP routing.

• EIGRP Authentication uses a shared secret key between routers to authenticate each other.

• It can be configured in two modes - MD5 authentication and SHA authentication.

• MD5 authentication is more commonly used and provides better security.

• SHA authentication is newer and provides stronger security.

• EIGRP Authentication can prevent unauthorized routers from participatin...read more

ECI MUX is a multiplexer used in telecommunications to combine multiple signals into one, while ECI Alarm is a system for monitoring and reporting faults in the network.

• ECI MUX stands for ECI Multiplexer, used to combine multiple signals into one for transmission over a single channel

• ECI Alarm is a system that monitors the network for faults and issues, providing alerts and notifications when problems occur

• ECI MUX and ECI Alarm are commonly used in telecommunications networks...read more

A trunk is a link that carries multiple VLANs, while untagged refers to a port that does not add VLAN tags to the frames it receives.

• A trunk is used to connect switches or routers and allows the transmission of multiple VLANs over a single link.

• Trunk ports add VLAN tags to the frames they receive and remove them when transmitting.

• Untagged ports are typically used to connect end devices and do not add or remove VLAN tags.

• Untagged frames are forwarded within the native VLAN of ...read more

Firewall works at the network layer.

• Firewall operates at the network layer of the OSI model.

• It filters and controls incoming and outgoing network traffic based on predetermined security rules.

• Examples of firewalls include hardware firewalls, software firewalls, and cloud-based firewalls.

VLAN stands for Virtual Local Area Network. It is a logical grouping of devices on a network based on their function, project or application.

• VLANs allow network administrators to segment a network into smaller, more manageable groups.

• Devices in a VLAN can communicate with each other as if they were on the same physical network, even if they are physically located on different switches.

• VLANs can improve network security by isolating sensitive data and restricting access to it....read more

A packet flows over the internet by being encapsulated in various network layers and routed through different devices.

• Packet is created at the application layer with data and destination IP address

• Packet is then encapsulated in a frame at the data link layer with source and destination MAC addresses

• Frame is transmitted over physical medium to the next hop based on routing table

• At each hop, the frame is decapsulated and re-encapsulated based on the destination IP address

• Packet...read more

SDH card is used in synchronous digital hierarchy networks to transmit data at high speeds. MUX is a device that combines multiple signals into one.

• SDH card is used in telecommunications to transmit data at high speeds

• MUX stands for multiplexer and is used to combine multiple signals into one

• SDH cards are commonly used in networking equipment like routers and switches

• MUX devices are used in various applications such as telecommunications and broadcasting

• Example: Cisco SDH car...read more

OSI works on the network layer.

• OSI (Open Systems Interconnection) model works on the network layer, which is Layer 3.

• The network layer is responsible for routing packets from the source to the destination across multiple networks.

• Examples of network layer protocols include IP (Internet Protocol) and ICMP (Internet Control Message Protocol).

IP Spoofing is a technique where an attacker impersonates another device by falsifying IP address in order to gain unauthorized access.

• IP Spoofing involves manipulating the source IP address in a packet to deceive the recipient.

• It is commonly used in DDoS attacks to hide the true source of the attack traffic.

• Prevention methods include implementing ingress and egress filtering on network devices.

• Examples of tools used for IP Spoofing include hping and Scapy.

VLAN stands for Virtual Local Area Network, used to logically segment a network into multiple broadcast domains.

• VLANs help improve network performance, security, and manageability by isolating traffic.

• Each VLAN is a separate broadcast domain, allowing for better control over network traffic.

• VLANs are configured at the switch level, with each port assigned to a specific VLAN.

• For example, VLAN 10 could be for the finance department, while VLAN 20 is for the marketing department...read more

ICM stands for Intelligent Contact Management and CVP stands for Customer Voice Portal. They are components of Cisco's contact center solutions.

• ICM is a call routing and reporting application used in contact centers to manage customer interactions.

• CVP is a self-service IVR (Interactive Voice Response) system that allows customers to interact with the contact center using voice or touch-tone inputs.

• Both ICM and CVP are key components of Cisco's contact center solutions, helpin...read more

RF devices can be connected using various methods such as Bluetooth, Wi-Fi, NFC, or wired connections.

• Identify the type of RF device and the available connectivity options

• Ensure that the device and the network are compatible

• Follow the manufacturer's instructions for pairing or connecting the device

• Test the connection to ensure proper functionality

There are several BGP attributes used for path selection and routing decisions.

• There are well-known BGP attributes like AS_PATH, NEXT_HOP, LOCAL_PREF, etc.

• There are optional BGP attributes like COMMUNITY, ORIGINATOR_ID, CLUSTER_LIST, etc.

• There are also extended BGP attributes introduced in newer versions of BGP.

• BGP attributes are used by routers to make routing decisions and determine the best path to a destination.

OSI (Open Systems Interconnection) layer is a conceptual model that describes the communication functions of a telecommunication or computing system.

• OSI model has 7 layers, each with a specific function

• Layer 1 (Physical) deals with physical connections and signals

• Layer 2 (Data Link) handles data packets and error correction

• Layer 3 (Network) manages routing and addressing

• Layer 4 (Transport) ensures reliable data transfer

• Layer 5 (Session) establishes and manages connections

• Laye...read more