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  1. 1. WEL COME
  2. 2. FIREWALL Presented By:Rameswar Mishra, 1151017007 Guided By-Ms. Rosalin Mahapatra, Dept. of CS&IT.
  3. 3. Contents          What is firewalls. Hardware vs softwares firewalls. Firewall Rules How does Software firewall work What a firewall can’t protect against Packet level filter Proxy server Conclusion Reference
  4. 4. 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
  5. 5. 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
  6. 6. Firewall Rules • Allow • Block • Ask
  7. 7. How does a software firewall work? • Inspects each individual “packet” of data as it arrives at either side of the firewall • Determines whether it should be allowed to pass through or if it should be blocked
  8. 8. What a Firewall Cannot Protect Against • Trojan horse • Social engineering • Physical outrages
  9. 9. Packet-level filter A category of firewall that provides a high degree of convenience, but a relatively low level of security. A packet-level filter blocks or forwards a packet solely on its merits, without taking into account past history; the filter may also look at the source and destination address information contained in the packet.
  10. 10. Application-level filter A category of firewall that provides a high degree of security but at the cost of lower speed and greater complexity. Typical application-level filters can provide proxy services for applications and protocols such as Telnet, FTP and HTTP
  11. 11. Proxy server • proxy server is a computer that offers a computer network service to allow clients to make indirect network connections to other network services. • A proxy server can also serve as a firewall.
  12. 12. How Proxy Server Works
  13. 13. Windows XP Firewall • Enable under Start -> Settings -> Control Panel • Select Local Area Connection • Select the Properties button • Click the “Advanced” tab
  14. 14. Windows XP firewall
  15. 15. Conclusion A firewall is a necessity if you are going to connect your LAN to the Internet. Firewalls can examine the traffic coming into and going out of your LAN and make decisions on what kinds of traffic to permit or deny .
  16. 16. • Ingham, Kenneth; Forrest, Stephanie (2002). "A History and Survey of Network Firewalls • firewall/network-layer-firewall
  17. 17. THANK YOU