Cisco CCNA Questions and Answers 2015 – Blog

Cisco CCNA Questions and Answers 2015

The CCNA certification is a highly reputable credential in the IT industry. It validates one’s competence in networking fundamentals, network access, IP connectivity, IP services, security fundamentals, and automation and programmability. The release of the CCNA questions and answers for the year 2015 provides an opportunity for aspiring network professionals to test their knowledge and prepare for the certification exam.

Question 1: What is the difference between a hub and a switch?

Answer: A hub operates at the physical layer of the OSI model, whereas a switch operates at the data link layer. Hubs broadcast incoming data to all connected devices, while switches analyze the data and forward it only to the intended recipient.

Question 2: What is the purpose of subnetting?

Answer: Subnetting allows for the partitioning of a network into smaller subnetworks, enabling better network management, improved performance, and enhanced security. It helps in optimizing the allocation of IP addresses and minimizing broadcast domains.

Question 3: What is the significance of the OSI model?

Answer: The OSI (Open Systems Interconnection) model is a conceptual framework that standardizes the functions of a network into seven layers. It assists in understanding network protocols, troubleshooting network issues, and promoting interoperability between different vendors’ networking devices.

Question 4: What is the purpose of VLANs?

Answer: VLANs (Virtual Local Area Networks) divide a single physical network into multiple logical segments, allowing for improved network performance, security, and management. They enable the grouping of devices based on specific criteria, such as department or function, regardless of their physical location.

Question 5: What is the difference between TCP and UDP?

Answer: TCP (Transmission Control Protocol) is a connection-oriented protocol that guarantees the reliable delivery of data packets. It establishes a virtual communication channel between the sender and receiver and ensures the packets arrive in the correct order. UDP (User Datagram Protocol), on the other hand, is a connectionless protocol that does not guarantee the delivery of packets. It is commonly used for time-sensitive applications, such as real-time video streaming or voice over IP (VoIP).

Question 6: How does NAT (Network Address Translation) work?

Answer: NAT is a technique used to translate private IP addresses used within a local network into public IP addresses used on the internet. It allows multiple devices within a network to share a single public IP address, conserving the limited pool of IPv4 addresses. NAT operates by modifying the source and/or destination IP addresses of packets as they traverse between the local network and the internet.


These CCNA questions and answers from 2015 provide valuable insights into the fundamental concepts of networking. By thoroughly understanding and practicing these concepts, aspiring network professionals can enhance their knowledge and increase their chances of success in the CCNA certification exam. Stay updated with the latest CCNA resources to stay ahead in the ever-evolving field of networking.

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