Introduction of firewall slides
- 2. Define what is firewall ? Need of firewall Types of firewall › Hardware firewall Advantage and disadvantage › Software firewall Advantage and disadvantage
- 3. Types of firewall techniques › Packet filter Drawback of packet filtering › Application gateway advantage › Circuit-level gateway › Bastion host What a personal firewall can do What a personal firewall can not do Manufacturing companies
- 4. Firewall is device that provides secure connectivity between networks(internal/external).
- 5. A firewall may be a hardware, software of a combination of both that is used to prevent unauthorized program or internet users from accessing a private network or a single computer. All message entering or leaving the intranet pass through the firewall, which examines each message & blocks those that do not meet the specified security criteria.
- 6. To protect confidential information from those who do not explicitly need to access it. To protect our network & its resources from malicious users & accidents that originate outside of our network.
- 7. Hardware firewall Software firewall
- 8. It is a physical device. It can be installed between the modem and computer. It can be incorporated into a broadband router being used to share the internet connection.
- 9. Protect an entire network. Usually more expensive, header to configure E.g.- Cisco pix, netscreen, watchfuard etc.
- 10. Uses very little system resources. More secure Enhanced security control Dedicated hardware firewalls are typically more reliable Easy to disable or remove Work independently of associated computer system.
- 11. Install process is more demanding both physically and mentally. Takes up physical work space More expensive Harder to upgrade and repair
- 12. It is a software application. It is installed onto the computer system that you wish to protect .
- 13. Protect a single computer This is usually the computer with modem attached to it. Usually less expensive, easier to configure E.g.- Norton internet security, MacAfee internet security etc.
- 14. Considerably cheaper or even free. Simple to install and upgrade Requires no physical changes to hardware or network Ideal for home/family use Takes up no physical space.
- 15. Software may crash or be incompatible with system Can be difficult to completely disable & especially remove Software bugs may compromise security Can be resource hungry Incompatibilities with OS.
- 16. Packet filter Application gateway/proxy server/proxy application gateway Circuit-level gateway Bastion host
- 17. It looks at each packet entering or leaving the network accepts or rejects it based on user-defined rules. Applications Presentations Sessions Transport Data Link Physical Data Link Physical Router Applications Presentations Sessions Transport Data Link Physical Network Network
- 18. Packet filtering is fairly effective & transparent to users, but it is difficult to configure. In addition, it is susceptible to IP spoofing.
- 19. Drawback of packet filtering technique:- i. Packet filtering rules can be complex. ii. Logging facility is not provided by such firewall. iii. If TCP/IP packet filtering is not implemented fully, it can lead to security hole. iv. Cannot handle RPC (remote produce calls)
- 20. In such type of firewall remote host or network can interact only with proxy server, proxy server is responsible for hiding the details of the internal network i.e. intranet. Users uses TCP/IP application, such as FTP & Telnet servers.
- 21. Applications Presentations Sessions Transport Data Link Physical Network Data Link Physical Applications Presentations Sessions Transport Data Link Physical Application Gateway Applications Presentations Sessions Transport Network Network Telnet HTTPFTP
- 22. This is very effective, but can impose a performance degradation.
- 23. Advantages of application gateway:- i. Less complex filter rules ii. Cost effectiveness iii. Robust authentication & logging facility iv. Proxy authenticates only those services for v. Which it is configured/installed.
- 24. It is a stand alone application. It does not permit end-to-end TCP connection. it sets up 2 TCP connection:- • Between itself and a TCP user on an inner host. • Between itself and a TCP user on an outer host.
- 25. Bastion host is a special purpose computer on a network specifically designed and configured to withstand attacks.
- 26. It generally hosts a single application, provides platform for application gateway and circuit-level gateway. It supports limited/specific applications to reduce the threat to the computer. Include application-Telnet, SMTP, FTP
- 27. Stop hackers from accessing your computer. Protect your personal information. Blocks “pop up” ads and certain cookies. Determines which programs can access the internet. Block invalid packets.
- 28. Cannot prevent e-mail viruses -only an antivirus product with update definitions can prevent e-mail viruses. After setting it initially, you cannot forget about it -The firewall will require periodic updates to the rule sets and the software itself.
- 29. Cisco system, Inc. Nortel networks corporation Juniper networks, Inc. MacAfee, Inc. 3com corporation Citrix systems, Inc