HCLTech Lead Engineer Interview Questions, Process, and Tips

VDC stands for Virtual Design and Construction. Supervisor oversees VDC process.

• VDC is a process of creating a digital model of a construction project before it is built.

• It helps in identifying and resolving potential issues before construction begins.

• Supervisor oversees the VDC process to ensure that the digital model is accurate and meets the project requirements.

• VDC can also help in improving communication and colla...read more

VSL is the voltage at which the substrate current becomes zero in VSS.

• VSL is the voltage at which the substrate current becomes zero in VSS.

• It is the minimum voltage required to maintain a zero substrate current.

• VSL is important in VSS as it helps in reducing the leakage current.

• It is achieved by applying a negative voltage to the substrate.

• VSL is typically set to -0.5V or -1.0V in modern CMOS processes.

MLAG is a protocol used for creating a loop-free network topology. LACP and PAGP are link aggregation protocols.

• MLAG stands for Multi-Chassis Link Aggregation Group.

• It allows multiple switches to appear as a single logical switch to the connected devices.

• LACP (Link Aggregation Control Protocol) is an IEEE standard protocol used for link aggregation.

• PAGP (Port Aggregation Protocol) is a Cisco proprietary protocol used f...read more

BGP path attributes used to manipulate ingress traffic and transit via 3rd AS.

• AS Path attribute is used to manipulate ingress traffic by adding or removing AS numbers.

• Local Preference attribute is used to influence the path selection within the same AS.

• MED (Multi-Exit Discriminator) attribute is used to influence the path selection between different ASes.

• Communities attribute is used to tag routes and influence the pat...read more

BGP community is a way to tag routes with additional information. It helps in controlling the flow of traffic.

• BGP community is a 32-bit number that can be attached to a route advertisement.

• It is used to tag routes with additional information.

• It helps in controlling the flow of traffic by allowing network administrators to manipulate the way BGP routes are propagated and selected.

• BGP communities can be used to implement...read more

VTep is a virtual tunnel endpoint used in VXLAN to extend Layer 2 networks over Layer 3 networks.

• VTep is a software-based endpoint that terminates VXLAN tunnels.

• It is used to extend Layer 2 networks over Layer 3 networks.

• VXLAN header encapsulates the original Ethernet frame and adds a 24-bit VXLAN Network Identifier (VNI) to identify the virtual network.

• The VLAN data is encapsulated with VXLAN header and fields like VN

Leaf and spine architecture is a network topology used in Cisco ACI for scalable and efficient data center networking.

• Leaf switches connect to spine switches, which then connect to the core network.

• Leaf switches handle traffic within their own pod, while spine switches handle traffic between pods.

• ACI uses a 2-tier spine-leaf architecture for scalability and flexibility.

• The spine switches act as the routing backbone, wh...read more

Nexus 9K hardware models used in Leaf and spine architecture.

• Nexus 9372PX and 9372TX used as leaf switches

• Nexus 9504, 9508, and 9516 used as spine switches

• Nexus 93108TC-EX and 93180YC-EX also used as leaf switches

• All models support VXLAN and ACI

• Highly scalable and flexible architecture

L3 fabric is a network architecture that provides high-speed and low-latency connectivity between devices. COOP is a protocol used for failover and redundancy in networking.

• L3 fabric is a type of network architecture that uses Layer 3 routing to provide high-speed and low-latency connectivity between devices.

• It is designed to be scalable and flexible, allowing for easy expansion and modification of the network.

• COOP (Cl...read more

EPG is Electronic Program Guide used for TV listings. Contract iOS is used for EPG communication due to its reliability and security.

• EPG is a digital guide that provides information about TV programs and schedules.

• Contract iOS is a secure and reliable way to communicate EPG data between devices.

• EPG data can be accessed through set-top boxes, smart TVs, and mobile apps.

• EPG data includes program titles, descriptions, sta

OTV mechanism refers to Orbital Transfer Vehicle mechanism used for transferring payloads from one orbit to another.

• OTV mechanism is used for transferring payloads from one orbit to another

• It is commonly used in space missions to transfer payloads between different orbits

• OTV mechanism can be used to transfer payloads from low Earth orbit to geostationary orbit

• It is also used for transferring payloads from one planet to

Administrative distances are values used by IGPs to determine the best path for routing.

• Administrative distances are used to determine the trustworthiness of routing information received from different sources.

• Lower administrative distances are preferred over higher ones.

• Examples of IGPs and their default administrative distances include OSPF (110), IS-IS (115), and RIP (120).

OSPF should be priority over eBGP. Achieve this by manipulating administrative distance or metric.

• OSPF should be preferred over eBGP as it is an interior gateway protocol while eBGP is an exterior gateway protocol

• Manipulate administrative distance to make OSPF preferred over eBGP

• Manipulate metric to make OSPF preferred over eBGP

• Use route maps to manipulate the preference of OSPF over eBGP

• Example: set the administrative...read more