10+ HCLTech Network Engineer Interview Questions and Answers

NATting is a process of modifying network address information in packet headers, LSA types include Type 1, Type 2, Type 3, Type 4, Type 5, and Type 7, IPsec tunnel is a secure communication channel established between two devices.

• NATting stands for Network Address Translation, used to modify network address information in packet headers

• Types of LSA (Link State Advertisement) include Type 1 (Router LSA), Type 2 (Network LSA), Type 3 (Summary LSA), Type 4 (ASBR Summary LSA), Ty...read more

Network is a collection of interconnected devices that communicate with each other using protocols.

• DHCP (Dynamic Host Configuration Protocol) is a network protocol that automatically assigns IP addresses to devices on a network.

• A switch is a networking device that connects devices on a local area network (LAN) and forwards data packets between them.

• A router is a networking device that connects multiple networks and forwards data packets between them.

• IP (Internet Protocol) is ...read more

To check interface in a router, you can use the show interface command in the router's CLI.

• Access the router's CLI interface

• Use the 'show interface' command to display information about all interfaces on the router

• Check the status, IP address, and other relevant details of the specific interface

VTP stands for VLAN Trunking Protocol, used to manage VLAN configurations in a network. Ethernet is a widely used networking technology for local area networks.

• VTP is used to synchronize VLAN information across a network of switches.

• It helps in reducing the administrative overhead of managing VLANs individually on each switch.

• Ethernet is a standard for connecting computers and other devices in a local area network (LAN).

• It uses a protocol to control the way data is transmitte...read more

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.

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

• OSPF routers maintain a link-state database to build a topology map of the network.

• The shortest path tree is calculated based on the cost of links, wit...read more

VPN stands for Virtual Private Network, used to securely connect remote users or networks. VLAN stands for Virtual Local Area Network, used to segment network traffic.

• VPN allows users to securely access a private network over a public network like the internet

• VLAN divides a physical network into multiple virtual networks for better traffic management

• VPN encrypts data to ensure privacy and security during transmission

• VLAN helps in improving network performance by reducing broa...read more

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

• OSPF is a link-state routing protocol

• It uses Dijkstra's algorithm to calculate the shortest path

• OSPF routers exchange link-state advertisements (LSAs) to build a topology map of the network

• It supports VLSM (Variable Length Subnet Masking) and CIDR (Classless Inter-Domain Routing)

• OSPF is widely used in large enterprise networks and ISPs

MED stands for Multi-Exit Discriminator, a BGP attribute used to influence the path selection in a network.

• MED is a 32-bit value included in BGP updates to indicate the preferred path for outbound traffic.

• Lower MED values are preferred by BGP routers when selecting a route.

• MED is typically used to influence outbound traffic flow from one AS to another.

• MED is not mandatory and is only considered when comparing routes from the same neighboring AS.

• Example: Router A advertises a ...read more

VRF stands for Virtual Routing and Forwarding. It is a technology that allows multiple instances of a routing table to coexist within the same router.

• VRF enables multiple virtual routers to exist within a single physical router

• Each VRF instance maintains its own routing table and forwarding information

• VRF is commonly used in MPLS networks to segregate customer traffic

• VRF provides network segmentation and isolation for different customers or applications

HSRP stands for Hot Standby Router Protocol, a Cisco proprietary redundancy protocol used to provide high availability for network services.

• HSRP is used to provide redundancy for routers in a network by allowing multiple routers to work together in a group.

• One router is elected as the active router, handling traffic for the virtual IP address, while the other routers in the group act as standby routers.

• If the active router fails, one of the standby routers takes over as the n...read more

BGP, OSPF, and VPN are all protocols used in networking to facilitate communication and secure data transmission.

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

• OSPF (Open Shortest Path First) is an interior gateway protocol used to find the best path for routing within a single autonomous system.

• VPN (Virtual Private Network) is a technology that creates a secure and encrypted connection over a less se...read more

Configuration on firewall involves setting up rules and policies to control network traffic.

• Configure access control lists (ACLs) to allow or deny traffic based on source, destination, and port

• Set up virtual private networks (VPNs) for secure remote access

• Implement intrusion prevention systems (IPS) to detect and block malicious traffic

• Regularly update firewall firmware and review logs for security incidents

NATting stands for Network Address Translation, a process used to modify network address information in packet headers while in transit.

• NATting allows multiple devices on a local network to share a single public IP address

• It can be used to hide the internal network structure from the outside world for security purposes

• Types of NAT include Static NAT, Dynamic NAT, and Port Address Translation (PAT)