HCLTech Network Specialist Interview Questions and Answers

The OSI model is a conceptual framework that standardizes the functions of a telecommunication or computing system into seven layers.

• The OSI model stands for Open Systems Interconnection model.

• It helps in understanding how data is transferred between devices in a network.

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

• Examples of layers include physical layer, data link layer, network layer,...read more

RSTP stands for Rapid Spanning Tree Protocol, a network protocol used to prevent loops in Ethernet networks.

• RSTP is an improvement over the original Spanning Tree Protocol (STP) and converges faster in case of network changes.

• It uses port roles (root, designated, alternate, backup) to determine the best path for data transmission.

• RSTP also introduces the concept of edge ports and link types to optimize network performa...read more

Troubleshooting OSPF stuck in exstart stage

• Check if there are any network connectivity issues

• Verify if OSPF neighbor relationships are properly established

• Ensure that OSPF router IDs are unique

• Check for any mismatched OSPF parameters such as area IDs or network types

• Verify if there are any firewall rules blocking OSPF traffic

HSRP provides high availability by allowing multiple routers to work together as a single virtual router, while GLBP provides load balancing and redundancy by distributing traffic across multiple routers.

• HSRP allows for a standby router to take over in case the primary router fails, while GLBP allows for multiple routers to share the traffic load.

• HSRP uses a virtual IP address and a virtual MAC address, while GLBP uses...read more

MED stands for Multi-Exit Discriminator, a BGP attribute influencing route selection based on preference.

• MED is used in Border Gateway Protocol (BGP) to indicate the preferred path for incoming traffic.

• Lower MED values are preferred over higher ones when multiple routes exist.

• Example: If Router A has a MED of 100 and Router B has a MED of 200, Router A's route will be preferred.

• MED is only considered when routes are fr...read more

OSPF states define the stages of neighbor relationships and database synchronization in the OSPF routing protocol.

• Down: Initial state, no OSPF packets received.

• Init: OSPF packets received, but no acknowledgment yet.

• Two-Way: OSPF routers acknowledge each other, forming a neighbor relationship.

• ExStart: Routers negotiate the master/slave relationship for database exchange.

• Exchange: Routers exchange their link-state advert...read more

Overview of OSPF, BGP, STP, VTP, HSRP, VRRP, wireless, packet flow

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

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

• STP (Spanning Tree Protocol) prevents loops in Ethernet networks by blocking redundant paths

• VTP (VLAN Trunking Protocol) manages VLAN config...read more