CCNA Interview Questions and Answers PDF 2018

CCNA Interview Questions and Answers PDF 2018

Are you preparing for a CCNA (Cisco Certified Network Associate) interview in 2018? To help you succeed, we have compiled a comprehensive list of commonly asked CCNA interview questions along with their answers. Whether you are a fresh graduate or an experienced professional, these questions will give you an edge in your next CCNA interview.

1. What is the purpose of VLAN and how does it work?

VLAN, or Virtual Local Area Network, is a method to logically segment a local network into multiple broadcast domains. It helps to improve network performance, security, and scalability. VLANs operate on switches by grouping ports together, so devices in one VLAN cannot directly communicate with devices in other VLANs unless a routing device, like a router or Layer 3 switch, is used.

2. What is the difference between a switch and a hub?

A switch operates at the data-link layer (Layer 2) of the OSI model and provides better performance and security compared to a hub. Unlike a hub, a switch can examine the destination MAC address of an incoming frame and selectively forward it only to the port connected to the destination device. This reduces unnecessary network congestion and improves overall network efficiency.

3. Explain the three types of routing tables in Cisco devices.

In Cisco devices, there are three types of routing tables: connected, static, and dynamic. The connected routing table includes direct network connections, the static routing table is manually configured by the administrator, and the dynamic routing table is built by routing protocols (such as OSPF, EIGRP, or RIP) that exchange routing information with other routers to determine the best paths for data transmission.

4. What is the difference between TCP and UDP?

TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) are both transport layer protocols used for data transmission over networks. TCP provides reliable, connection-oriented communication with error checking, reliable data delivery, and congestion control. On the other hand, UDP is connectionless and provides faster, but unreliable, communication without any form of error checking or guaranteed delivery.

5. What is NAT and how does it work?

NAT (Network Address Translation) is a technique used to translate private IP addresses to public IP addresses and vice versa to enable communication between private networks and the internet. It works by mapping multiple private IP addresses to a single public IP address, allowing multiple devices to share a common public IP address. NAT operates at the network layer (Layer 3) of the OSI model.

6. Explain the OSI model and its seven layers.

The OSI (Open Systems Interconnection) model is a conceptual framework that standardizes the functions of a communication system into seven layers. These layers are: Physical, Data Link, Network, Transport, Session, Presentation, and Application. Each layer is responsible for specific tasks and provides services to the layer above and below it, ensuring reliable and interoperable communication across networks.

These are just a few examples of the CCNA interview questions and answers you can expect in 2018. To prepare yourself thoroughly for an upcoming CCNA interview, make sure to study topics like subnetting, routing protocols, network troubleshooting, and security. Good luck with your interview!

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