Network policies and security measures are needed to properly manage networks and protect systems and data. Client-server networks have servers that handle data storage and login requests while clients access this data. Peer-to-peer networks have equal sharing between computers. Disaster recovery plans are important in case systems fail, and backups ensure data can be restored if storage devices fail. Network managers must implement passwords, encryption, and user restrictions to secure systems, but new technologies have made networks harder to lock down as hackers can more easily exploit vulnerabilities.

1. Network Security and Policies A451 – Computing Theory

2. Get your brain logged on…! Think about the following questions: What are network policies? Why do we have network policies? Do you think they are needed?

3. By the end of this lesson: All of you will be able to explain the different roles of computers in a client-server and peer-to-peer network Most of you will be able to identify the security measures and network policies needed to run a network A few of you will be able to explain the need for security measures and justify network policies.

4. Client Server Network In a Client-server network, the server acts as the main computer handling login requests, user storage, etc. The client could be any computer. The user can log on to any client and still access their stuff on the server.

5. Peer-to-Peer Network In a Peer-to-peer network, each computer shares information equally and plays an equal role in the network.

6. Disaster Recovery In the event of the system failing there needs to be plans in place to get the network up and running again as quickly as possible. Many organisations, such as banks, have a disaster recovery plan which may mean relocating to a different location (if the building is no longer accessible). If there is a power cut, many networks have UPS (uninterrupted power supplies) which are large batteries with enough charge to keep the network going long enough to shut it down correctly.

7. Backups If a hard drive fails, there is usually a backup which can take the strain. Networks are often backed up at least daily and these backups are stored off-site or in a fire-proof safe so in the event of a disaster in the building, the data is still intact.

8. Your Task Log on to Computing wiki and go to Theory > Network Policies and Security Read the articles on the following links: “ Microsoft online services hit by major failure” “ Thousands lose vodafone service”

9. Your Task Using the articles answer the following: How long were the computer systems not available for? What impact did the failure have on customers and the business?

10. Network Security Methods of securing networks: Passwords Encryption User Restrictions

11. Your Task Log on to Computing wiki and go to Theory > Network Policies and Security Click on the link: “IT Security Article from BBC (19/11/10)” Read through the article.

12. Your Task Using the article answer the following: How did network managers historically “lock-down” systems? Explain how new technologies have made the job of securing the network more difficult. Give a specific example of how a new technology has been exploited by hackers.

13. Lesson Objectives Recap All of you will be able to explain the different roles of computers in a client-server and peer-to-peer network Most of you will be able to identify the security measures and network policies needed to run a network A few of you will be able to explain the need for security measures and justify network policies.