1. An Introduction to Firewalls By: David Moss, NUIT Technology Support Services Vince Celindro, NUIT Telecommunications and Network Services Robert Vance, NUIT Telecommunications and Network Services Barbara Mims, Office of Alumni Relations and Development

2. Agenda Firewall Basics for the Beginning User NUIT Firewall Offering Case Study – Desktop Firewall Software Implementation for the Office of Alumni Relations and Development Questions and Answers

3. What is a Firewall? A firewall is hardware, software, or a combination of both that is used to prevent unauthorized programs or Internet users from accessing a private network and/or a single computer

4. Hardware vs. Software Firewalls Hardware Firewalls –Protect an entire network –Implemented on the router level –Usually more expensive, harder to configure Software Firewalls –Protect a single computer –Usually less expensive, easier to configure

5. How does a software firewall work? Inspects each individual “packet” of data as it arrives at either side of the firewall Inbound to or outbound from your computer Determines whether it should be allowed to pass through or if it should be blocked

6. Firewall Rules Allow – traffic that flows automatically because it has been deemed as “safe” (Ex. Meeting Maker, Eudora, etc.) Block – traffic that is blocked because it has been deemed dangerous to your computer Ask – asks the user whether or not the traffic is allowed to pass through

7. What a personal firewall can do Stop hackers from accessing your computer Protects your personal information Blocks “pop up” ads and certain cookies Determines which programs can access the Internet

8. What a personal firewall cannot do Cannot prevent e-mail viruses –Only an antivirus product with updated definitions can prevent e-mail viruses After setting it initially, you can forget about it –The firewall will require periodic updates to the rulesets and the software itself

9. Considerations when using personal firewall software If you did not initialize an action and your firewall picks up something, you should most likely deny it and investigate it It’s a learning process (Ex. Spooler Subsystem App) If you notice you cannot do something you did prior to the installation, there is a good chance it might be because of your firewall

10. Examples of personal firewall software ZoneAlarm BlackICE Defender Tiny Personal Firewall Norton Personal Firewall ***Please be sure to read the license agreement carefully to verify that the firewall can be legally used at home and/or the office.

11. Windows XP Firewall Currently *not* enabled by default Enable under Start -> Settings -> Control Panel Select Local Area Connection Select the Properties button Click the “Advanced” tab

12. Windows XP firewall

13. Updates to Windows XP Firewall *Will* be enabled in default installations of Windows XP Service Pack 2 Ports will be closed except when they are in use Improved user interface for easier configuration Improved application compatibility when firewall is enabled

14. Mac OS X firewall *Not* enabled by default Enable under System Preferences Select Sharing Click “Firewall” tab Click “Start” button

15. Mac OS X firewall

16. NUIT Firewall Service

17. Why Netscreen? Comparison of the Big 3 –Hardware vs. Software –Transparent Mode vs. Routing Mode –Distributed Management –Pricing Models

18. The Process A Department requests a FW Consultation TNS Organizes a Meeting The Department Provides the List of Machines they want to Protect TNS Measures Bandwidth Requirements TNS Prepares a FW Proposal The Department Makes their Decision

19. The Process continued... TNS Installs the FW in a Passive State TNS Logs All Traffic from the Target Hosts TNS Develops a Rule Set The Department Oks the Rule Set TNS Activates the Rule Set Everyone's Happy =)

20. Final Notes Rule Management Default Allow vs. Default Deny Firewalls do NOT Solve the Entire Problem

21. Additional Information Visit the following websites: http://www.it.northwestern.edu/reference/firewall/firewall_strategies_wp.html http://www.juniper.net/netscreen_com.html Or simply email: –nsg-net@northwestern.edunsg-net@northwestern.edu –consulting-services@northwestern.edu