Firewall & packet filter new

Firewall & packet filter

1. GUJARAT TECHNOLOGICAL UNIVERSITY Subject : Cyber Security (2150002) Topic : Firewall and Packet filter

2. FIREWALL & PACKET FILTER

3. Contents What is FireWall ? Types of firewall Firewall Rules How does a Firewall work ? What a personal firewall can do ? Introduction to packet filter Functions of Packet Filter Usage of Packet Filters Manufacturing companies CONCLUSION

4. What is FireWall ? Firewall is device that provides secure connectivity between networks (internal/external). 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.

5. 1.Hardware firewall 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. Protect an entire network. Usually more expensive, header to configure E.g .- Cisco pix, netscreen, watchfuard etc.

6. 2.software firewall It is a software application. It is installed onto the computer system that you wish to 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.

7. Firewall Rules 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

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

9. How a firewall works ? Sniffing Mode An attacker tries to compromise a service on the protected network. 2 ) The Firewall identifies the attempt . LOG Alert Reset Fire Wall  The FIREWALL can now: Alert the admin Harden the firewall Or reset a TCP/IP connection

10. 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 .

11. Sample Network to Be Protected by a Firewall

12. Introduction to packet filter Packets: discrete blocks of data; basic unit of data handled by a network Packet filter: hardware or software designed to block or allow transmission of packets based on criteria such as port, IP address, protocol To control movement of traffic through the network perimeter, know how packets are structured and what goes into packet headers It looks at each packet entering or leaving the network accepts or rejects it based on user-defined rules. Packet filtering is fairly effective & transparent to users, but it is difficult to configure. In addition, it is susceptible to IP spoofing.

13. Applications Presentations Sessions Transport Data Link Physical Data Link Physical Router Applications Presentations Sessions Transport Data Link Physical Network Network

14. Functions of Packet Filter Control: Allow only those packets that you are interested in to pass through. Security: Reject packets from malicious outsiders Watchfulness: Log packets to/from outside world

15. Usage of Packet Filters Filtering with incoming or outgoing interfaces E.g ., Ingress filtering of spoofed IP addresses Egress filtering Permits or denies certain services Requires intimate knowledge of TCP and UDP port utilization on a number of operating systems

16. Manufacturing companies Cisco system, Inc. Nortel networks corporation Juniper networks, Inc. MacAfee, Inc. 3com corporation Citrix systems, Inc

17. Conclusion Don’t make the mistake of thinking that no one will attack your network, because with the rise in automated attack tools, your network is as much at risk as every other network on the Internet. The need for firewalls has led to their ubiquity. Nearly every organization connected to the Internet has installed some sort of firewall. When choosing and implementing a firewall solution, make a decision based on the organization's needs, security policy, technical analysis, and financial resources. Solutions available today utilize different types of equipment, network configurations, and software.