Advanced Higher Computing. Computer Networks. Homework Sheets

Transcription

1 Advanced Higher Computing Computer Networks Homework Sheets

2 Topic : Network Protocols and Standards. Name the organisation responsible for setting international standards and explain why network standards are needed.. What is the Request For Comments (RFC) system and why is it useful? 3. What is the Internet Corporation for Assigned Names and Numbers (ICANN) responsible for? 4. List the seven layers of the ISO network architecture model with a brief description of their function What is the difference between a connection oriented and a connectionless protocol? 6. List the different responsibilities of TCP and IP. 7. Draw a diagram mapping the layers of the ISO model with the Internet Architecture model. Total 0 Marks

3 Topic : IP Addressing and DNS. Explain how the three classes of IP address split up the four octets in an IP address between network identifiers and host identifiers.. Explain how a router can function without it being aware of the end to end link when forwarding IP packets. 3. What three limitations to the class system of IP addressing were subnets developed to solve? 4. What is Network Address Translation (NAT) and how can it help secure a Local Area Network? 5. Use the example CIDR address /6 to describe how CIDR operates 6. What function does the Domain Name Service (DNS) perform? 7. How can the following commands aid network troubleshooting? Ipconfig Ping Traceroute Total 0 Marks

4 Topic 3: Network Applications. Explain the difference between the three protocols; POP3, SMTP and IMAP. What headers are added to an message before it is received by an client? 3. Why was a password not needed in the original specification of SMTP? 4. What restrictions to the original specification was MIME designed to get around? 5. What are the disadvantages of MIME? 6. What are the three component parts of an HTML Document? 7. What is the advantage of using stylesheets when designing a web site? 8. Describe what should be considered when designing a web site? Total 0 Marks

5 Topic 4: Network Applications. List the three ways in which multimedia content can be dealt with by a browser.. Explain the difference between a Java applet and an ActiveX control. 3. What error code would an HTTP server generate if a non-existent page was requested by a client? 4. Both FTP and HTTP are file transfer protocols. What are the main differences between them? 5. Describe the role of HTTP when a user requests a web page by typing a URL into a browser. 6. What is the function of a Proxy Server in a Local Area Network? 7. When would Gateway be used to request a web page? 8. What is Voice Over Internet Protocol (VOIP)? 9. What techniques are used in order to compress video information when using the Internet for Video Conferencing? Total 0 Marks

6 Topics 5 & 6: Network Security and Denial of Service Attacks. How does Asymmetric encryption differ from Symmetric encryption and how does it overcome the main limitation of Symmetric encryption?. Why does Asymmetric encryption make message authentication possible? 3. Why do digital certificates have to be authenticated? 4. Describe how we classify the strength of an encryption system. 5. The Ping of Death is a buffer overflow attack how can a buffer overflow be exploited by an attacker and what measures can be used to counteract attacks like this? 6. Name two bandwidth consumption attacks and describe how they can be counteracted. 7. What is a Distributed Denial of Service Attack (DDoS)? 8. What is the difference between a virus a worm and a Trojan? Total 0 Marks

7 Topic 7: Network Protection. What are the limitations of using a Proxy server and Network Address Translation (NAT to protect a Local Area Network?. Why is a firewall needed? 3. Why might a router not be able to do the same job as a firewall? 4. List the services you would leave the ports open for when initially setting up a firewall. 5. What are the differences between a full backup, a differential backup and an incremental backup? 3 6. What are the limitations of a remote backup? Total 0 marks

8 Topic 8: Data Transmission. What were the benefits of moving from coaxial cable to Unshielded Twisted Pair (UTP) cable for setting up an Ethernet network?. What are the advantages and disadvantages of using of Fibre Optic Cable for an Ethernet network? 3. Explain the difference between a hub and a switch, and how a switch can benefit the data transfer rate in a Local Area Network. 4. Explain the difference between a Bridge and a Router with reference to the OSI layers they operate at. 5. Explain the difference between analogue and digital bandwidth. 6. What are the implications of the inverse square law when manufacturers try to increase the amount of data carried by a wireless signal. 7. What are the advantages of the 80.a wireless standard over the 80.b standard and what are the disadvantages? 8. Describe three ways in which a Wireless Local Area Network (WLAN) could be secured. Total 0 Marks

9 Topic 9: Remote Access Protocols. Why is an ADSL connection unsuitable for high quality Video Conferencing?. When would an organisation need o use a leased line rather than an ISDN connection? 3. Why is a Virtual Private Network (VPN) a better solution to remote working than direct dialup to a network? 4. Why is the V90 modem standard asymmetric? 5. What are the advantages of the Point to Point Protocol (PPP) over the Serial Line Internet Protocol (SLIP)? 6. Explain what Tunnelling means when transferring packets of data across a Virtual Private Network 7. Why does IP Security (IPSec) need to use asymmetric encryption? Total 0 Marks