About Firewall. Its description. Uses etc..

2. Contents
 Introduction to Firewall
 Generations of Firewall
 Types of Firewall
 Firewall Topology
 Firewall Rules
 Conclusion
 References

3. Introduction to Firewall
What is Firewall?
 Firewall is a network security system
that controls the incoming and
outgoing network traffic based on
applied rules.
 It establishes a barrier between a
trusted, secure internal network and
another network ( e.g., the Internet)
that is assumed not to be secure and
trusted.

5. Generations of Firewall
First Generation : Packet Filter
STATIC PACKET FILTERS
• One of the simplest and least
expensive forms of firewall
protection is known as static packet
filtering.
• Each packet entering or leaving the
network is checked and either
passed or rejected depending on set
of user-defined rules.

6. STATEFUL PACKET INSPECTION
• Within the same generation of static
packet filtering firewalls are
firewalls known as Stateful packet
inspection.
• It examines the contents of packet
rather than just filtering them, it
consider their contents as well as
their addresses
Generations of Firewall
First Generation :

7. Second Generation Firewalls
PROXY SERVICES
• The next generation of firewalls
attempted to increase the level of
security between trusted and
untrusted networks.
• The Proxy program evaluates data
sent from the client and decides
which to pass on and which to drop.

8. Third Generation
 This new generation evolved to meet
the major requirements demanded by
corporate networks f increased
security while minimizing impact.
 The requirement of this generation of
firewalls will be more demanding due
to growing supports for VPNS ,
wireless communication , and
enhanced virus protection.

9. Types of Firewall
HARDWARE FIREWALLS
• Hardware firewalls can be effective
with little or no configuration, and
they can protect every machine on
local networks.
• Hardware firewall uses packet
filtering to examine the header of a
packet to determine its source and
destination.

10. Types of Firewall
SOFTWARE FIREWALLS
• Software firewalls are to be installed
on individual home users and you
can customize it; allowing some
control over its function and
protection features.
• It could also provide protection
against the most common Trojan
programs or e-mail worms.

11. Firewall Topology
SCREENED SUBNET
• This architecture uses a single
firewall with three network card.
• It provides a solution that allows
organizations to offer services
securely to internet users.

12. Firewall Topology
DUAL FIREWALLS
• In this case, the DMZ is placed
between the two firewalls.
• The use of two firewalls still allows
the organization to offer services to
Internet users through the use of a
DMZ.

13. 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 : Ask the user whether or not the
traffic is allowed to pass through.

14. How Firewalls Work
 IP addresses : A typical IP address
looks like: 216.27.61.137.
 Domain Names : A company might
lock all access to certain domain
names or allow access only to specific
domain names.
 Ports : If server machine is running a
Web server and an FTP server , the
web server would be on port 80 and
FTP on 21 port.

15. WHAT FIREWALL CAN’T DO
 Can’t protect you against malicious
insiders.
 Can’t protect you against connections
that won’t go through it.
 Can’t protect you against completely
new threat.
 Can’t protect against viruses.

16. Some Good Firewalls
ZoneAlarm Firewall
Comodo Firewall
Tinywall

17. Conclusion
 Whatever firewall you currently use
or are considering the most important
thing is to match the product with
specific security requirements of your
organization.

18. References
 www.wikipedia.com
 www.techrepublic.com
 www.wibopedia.com
 www.searchsecurity.techtarget.com
 www.howstuffworks.com

19. Queries??