Download Exam Questions: Internetworking & Security for Software & Networking Students and more Exams Computer Networks in PDF only on Docsity! Cork Institute of Technology Bachelor of Science (Honours) in Software Development and Computer Networking - Stage 3 (KDNET_8_Y3) Autumn 2008 Internetworking and Security (Time: 3 Hours) Answer any FOUR questions All questions carry equal marks Examiners: Dr. J. Buckley Dr. A. Kinsella Ms. Olivia Brickley Q1. a. Illustrate and describe three Frame Relay topologies, outlining the problems and benefits of each. (9 marks) b. Briefly describe frame relay error handling considerations. (3 marks) c. How are multiple frame relay connections configured over one physical connection? (2 marks) What is split horizon? Explain, using a diagram, how it causes problems in frame relay networks. How is this issue resolved? (5 marks) d. Frame relay uses the concept of virtual connections. Describe how addressing is handled, considering both layer 2 and layer 3 considerations. (6 marks) Q2. a. Multicast is based on the concept of a group. Describe, using illustrations where necessary, basic IGMP protocol operation. (5 marks) Briefly discuss the differences between IGMPv1 and IGMPv2 (3 marks) b. The two basic types of multicast distribution trees are source trees and shared trees. Using a simple example, describe and demonstrate their operation. (8 marks) c. RIP is a well known distance vector routing protocol. Identify and describe five limitations associated with RIP. (5 marks) Describe how OSPF it overcomes these limitations. (4 marks) Q3. a. What are the desired properties of a digital signature? (4 marks) 2 Describe the digital signature process using public-key cryptography, identifying how/where these properties are assured h b. Network security is a continuous process built around a security policy. Describe each step in the security wheel. (8 marks) c. What is a VPN and how does it operate? (1 marks) VPNs use IPSec for security. Illustrate and explain the differences between AH and ESP, also outlining their strengths and/or weaknesses. (6 marks) Q4. a. HDLC is an important protocol whose variants are used in many different technologies. Briefly describe its purpose and functionality. (6 marks) What is bit stuffing and why is it used? (3 marks) b. PPP has two authentication methods. Describe in detail the operation of CHAP. (5 marks) How does this differ from PAP? (2 marks) c. What is the hidden terminal problem in WiFi networks? (3 marks) Describe in detail how the 802.11 standard addresses this issue. (6 marks)
