2. P RESENTED B Y - Subhomita Gupta Roll no: 10

3. T OPICS TO BE DISCUSS ARE : Introduction to Firewalls  History Working of Firewalls Needs Advantages and Disadvantages Kinds Users of Firewalls  By  For

4. I NTRODUCTION A firewall is a piece of hardware or software program which protects a computer or network from attacks from intruders and hackers. A firewall is a set of related programs, located at a network gateway servers, that protects the resources of a private network from users from other networks.

5. Firewall Architecture

6. H ISTORY 1 st Generation (Past) : The first network firewalls appeared in the late 1980s and were routers used to separate a network into smaller LANs. The first security firewalls were used in the early 1990s. They were IP routers with filtering rules. These firewalls were effective, but limited. It was often very difficult to get the filtering rules right.

7. C ONTINUE …. 2 nd Generation (Present) : Today’s firewalls are more reliable and has strong user authentication. It works on the concept of VPN (Virtual Private Network). They also include virus scanning, URL screening, and keyword scanners

8. C ONTINUE …. 3 rd Generation (Future) : In future there would be 3G firewalls with more enhanced features like virtual private networking (VPN), intrusion detection systems (IDSs), and virus scanning in more enhanced way. These firewalls can handle 100s of Mb’s of throughput. There would be specialized firewall.

9. W ORKING O F F IREWALLS A firewall system contains a set of predefined rules that allow the system to: Authorize the connection (allow) Block the connection (deny) Reject the connection request without informing the issuer (drop)

10. F UNCTIONS Blocking Incoming Traffic depending on Source. Blocking based on website Content. Allocates Internal Resources. Blocking Selected Outgoing Traffic. Make reports on all network traffic, network activity and so on.

11. C ONTINUE …. Checking the information in packets. It is part of the network perimeter defense of an organization and should enforce a network security policy. Able to efficiently log inter-network activity, and limit the exposure of an organization.

12. N EEDS To protect for following: Loss and Manipulation of Data Business Secrets and Confidential Data Hijacked Networks Loss of Reputation

13. A DVANTAGES OF A SOFTWARE FIREWALL Following are the advantages of software firewall :  Free or cheap to install  Easy to install (Usually involves set up wizard)  Specialist skills not needed for configuration  Levels of access can be set

14. D ISADVANTAGES OF A SOFTWARE FIREWALL Following are the disadvantages of software firewall :  May slow down applications  May be heavy on system resources  Can be difficult to remove  Every host needs to be updated regularly (patches)  No centralized management

15. Software Firewall

16. A DVANTAGES OF A HARDWARE FIREWALL Following are the advantages of hardware firewall :  Centralized management possible  Secure  Fast  Less interference

17. D ISADVANTAGES OF A HARDWARE FIREWALL Following are the disadvantages of hardware firewall :  Expensive to purchase  Specialist knowledge may be required to install and configure  Takes up physical space  Hard to upgrade

18. Hardware Firewall

19. T YPES O F F IREWALLS According to users:  Personal Firewalls for Home Users and Individuals  Firewalls for Home Businesses or Small Business  Enterprise or large Business Firewalls

20. C ONTINUE …. According to functions (Basic):  Network Layer  Application Layer

21. N ETWORK L AYER : These generally make their decisions based on the source, destination addresses and ports in individual IP packets. Network layer firewalls tend to be very fast and tend to be very transparent to users. A network layer firewall is called as ``screened host firewall‘’.

22. Network Layer Firewall

23. A PPLICATION L AYER : These generally are hosts running proxy servers, which permit no traffic directly between networks, and which perform elaborate logging and auditing of traffic passing through them. Application layer firewalls can be used as network address translators.

24. Application Layer Firewall

25. C ONTINUE …. According to categories:  Packet filters  Circuit level gateways  Application level filters  Dynamic packet filters  Distributed firewalls

26. F IREWALLS U SED …. By:  Anyone who is responsible for a private network that is connected to a public network needs firewall protection.  Anyone who connects so much as a single computer to the Internet via modem.

27. F IREWALLS U SED …. For:  It is generally used to prevent Internet users from gaining access to a private or corporate network.  It can be used to control which Internet service are available to users of the corporate network on the other side of the firewall.