1. Can you explain the purpose and function of VLANs (Virtual Local Area Networks) in a network?
VLANs segregate network traffic into separate logical networks, enhancing security, reducing broadcast domain size, and facilitating better network management and scalability.
2. What is the difference between Layer 2 and Layer 3 switches? When would you use each?
Layer 2 switches operate at the data link layer, forwarding traffic based on MAC addresses, while Layer 3 switches operate at the network layer, making routing decisions based on IP addresses; Layer 2 switches are typically used within a single subnet for basic connectivity, while Layer 3 switches are employed for inter-VLAN routing and more advanced network segmentation.
3. Describe the process and protocols involved in establishing a VPN (Virtual Private Network) connection.
: A VPN connection is established through protocols like IPSec, SSL/TLS, or L2TP, which authenticate and encrypt data between the client and the VPN server, ensuring secure communication over the public internet.
4. How do you troubleshoot common issues with OSPF (Open Shortest Path First) routing protocol?
To troubleshoot OSPF issues, check for common problems such as mismatched OSPF network types, area mismatches, authentication mismatches, and ensure proper adjacency formation between OSPF routers.
5. Explain the concept of Quality of Service (QoS) in networking and its significance
Quality of Service (QoS) ensures that certain types of network traffic receive priority treatment to meet specific performance requirements, such as minimizing latency for real-time applications like VoIP or video streaming, thus enhancing overall network performance and user experience
6. What is EtherChannel, and how does it improve network performance and redundancy?
: EtherChannel is a technology that bundles multiple physical Ethernet links into a single logical link, increasing bandwidth and providing redundancy by distributing traffic across the aggregated links, thus improving network performance and resilience
7. Discuss the advantages and disadvantages of static routing versus dynamic routing protocols.
Static routing offers simplicity and control but lacks scalability and adaptability to network changes, while dynamic routing protocols like OSPF and BGP provide automatic route updates and fault tolerance but require more configuration and overhead.
8. Can you describe how Spanning Tree Protocol (STP) works and its role in preventing network loops?
Spanning Tree Protocol (STP) elects a loop-free path in a network by blocking redundant links to prevent loops, ensuring there's only one active path between switches, thus preventing broadcast storms and network congestion.
9. How do you secure network devices using features like Access Control Lists (ACLs) and port security?
Network devices can be secured using ACLs to control traffic flow based on defined rules and port security to restrict access by limiting the number of MAC addresses or types of devices allowed on a switch port.
10. Explain the process of configuring and verifying HSRP (Hot Standby Router Protocol) for high availability.
To configure HSRP for high availability, you assign virtual IP addresses and prioritize one router as the active router while the other remains in standby mode; verification involves checking the status and priority of routers using commands like "show standby
