Firewallpresentation 100826052003-phpapp02(1)
- 1. PRESENTERS :- VARUN SACHDEVA ABHISHEK KHYATI MATHUR PRABHDEEP KAUR Presentation :’Firewalls’ 1
- 2. Introduction FireWall is device that provides secure connectivity between networks.. A firewall may be a 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. 2
- 3. Hardware vs. Software Firewalls 3 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
- 4. How does a software firewall work? 4 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
- 5. Types of Firewalls Common types of Firewalls: 1. Packet-filtering routers 2. Application-level gateways1 3. Circuit-level gateways1 5
- 6. 6 ◦ Packet-filtering Router • Applies a set of rules to each incoming IP packet and then forwards or discards the packet ◦ Filter packets going in both directions ◦ The packet filter is typically set up as a list of rules based on matches to fields in the IP or TCP header ◦ Two default policies (discard or forward)
- 7. 7 Packet Filtering Firewall Trusted Network Firewall rule set Packet is Blocked or Discarded Untrusted Network
- 8. 8 Packet Filtering Firewall A packet filtering firewall is often called a network layer firewall because the filtering is primarily done at the network layer (layer three) or the transport layer (layer four) of the OSI reference model.
- 9. 9 Application-level Gateway Gateway sits between user on inside and server on outside. Instead of talking directly, user and server talk through proxy. Allows more fine grained and sophisticated control than packet filtering. For example, ftp server may not allow files greater than a set size. A mail server is an example of an application gateway ◦ Can’t deposit mail in recipient’s mail server without passing through sender’s mail server host-to-gateway ftp session gateway-to-remote host ftp session application gateway
- 11. 11 Circuit-level Gateway 1. Stand-alone system 2. Specialized function performed by an Application-level Gateway 3. Sets up two TCP connections 4. The security function consists of determining which connections will be allowed 5. Typically use is a situation in which the system administrator trusts the internal users
- 13. Firewall Rules 13 Allow – traffic that flows automatically because it has been deemed 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
- 14. Making The Firewall Fit IP address Domain names Protocols 14
- 15. What It Protects You From Remote login Simple Mail Transfer Protocol session hijacking Operating system bugs Spam 15
- 16. 16 Conclusion
- 17. 17 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. • Block invalid packets.
- 18. 18 • 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 cannot forget about it – The firewall will require periodic updates to the rulesets and the software itself.
- 19. 19 Thank you