The document presents a seminar on firewalls, detailing their definitions, types, advantages, and disadvantages. Firewalls serve as security barriers for networks, originating in the late 1980s, and can be classified into hardware, software, host-based, and network-based types. The conclusion emphasizes the importance of firewalls in protecting private networks while acknowledging their limitations in guarding against various forms of malware.

1. Seminar Topic
FIREWALL
Presented BY:
Saloni Mittal
Roll No-1946386
BANASTHALI VIDYAPITH

2. TABLE OF CONTENT
INTRODCUTION
HISTORY
FIREWALL
HARDWARE & SOFTWARE FIREWALL
HOST-BASED FIREWALL
NETWROK-BASED FIREWALL
PACKET-FILTERING FIREWALL
APPLICATION LEVEL GATEWAY
STATEFULMULTI-LAYER INSPECTION
ADVANTAGES& DISADVANTAGES
CONCLUSION
REFERENCES

3. INTRODUCTION
The Internet has made large amount of information available to the
average computer user at home, in business and education.
For many people, having access to this information is no longer just an
advantage.
Therefore, security of network is the main criteria here and
firewalls provide this security.
It is used to monitor and control over all incoming and outgoing
network traffic of your system. It is based on advanced and a defined set
of security rules.

4. HISTORY
Firewall technology first began to emerge in the late 1980s
The Morris Worm spread itself through multiple
vulnerabilities in the machines of the time.
The First paper published on firewall was in 1988 by
Jeff Mogul.
First generation : Packet Filters
Second generation: Application Level Gateway
Third generation : “ Stateful " Filters

5. FIREWALL
Firewalls separate your device from the Internet using a
“wall of code”.
Firewall is a software program that can be considered as a
security tool for your PC. We use it to enhance the security of
computers connected to a network.
It verifies each individual “data packet” arrives at either side
of the firewall. After that it decides whether to pass it or not.

6. HARDWARE & SOFTWARE FIREWALL
Hardware firewalls can provide better security and reduce
the performance loss by using dedicated memory and
processing power .
Most hardware firewalls will have a minimum of four
network ports to connect other computers.
It was expensive
Suitable for larger organizations
CISCO- ASA NGFW
FORTINET- FORTIGATE
CYBERROAM-UTM FIREWALL
HARDWARE FIREWALL

7. SOFTWARE FIREWALL
Software firewalls are installed on your computer or server computer like
any other software .
A software firewall will protect your computer from unauthorized access to
the network or home pc.
Most software firewall it provides protection against Trojan programs,
e-mail worms, antivirus.
It was cheaper than hardware
It wasn’t complex
Can be easily installed
Ideal for individual users
COMODO,GLASSWIRE,AVS FIREWALL.

8. Host based
Network based firewall
TYPES OF FIREWALL

9. HOST BASED
A host-based firewall is installed on an individual
computer connected to network.
These types of firewalls are the way to protect individual
host from infections throughout the network.
Used in a small organization.
example-home ,office work , Business.

10. HOST BASED

11. NETWORK BASED FIREWALL
It monitors traffic to and from all devices on the network.
A network-based firewall is implemented at a specified point in the
network path between private network and internet.
It is combination of hardware and software firewalls.

12. NETWORK BASED FIREWALL
PUBLIC

13. METHODS:
1 32

14. A packet filtering firewall applies a set of rules to each incoming
and outgoing IP packet and the forwards or discards the packet
Filtering rules are based on information contained in a network
packet
- Source IP address
- Destination IP address
- Source and destination transport level address
- IP protocol field
It looks at each packet entering or leaving the network accepts or
rejects it based on user-defined rules
1-PACKET FILTERING
(Relative simplicity)

15. PERMISSION IPADDRESS PROTOCOL DESTINATION PORT
ALLOW 162.213.214.140 TCP ANY 80
ALLOW 54.21.66.112 TCP ANY 80
DENY 40.550130.66 TCP ANY 80
162.213.214.140
54.21.66.112
40.550.130.66
PACKET FILTERING
PUBLIC PRIVATE

16. It is also known as PROXY server , which is established
between your provider and internet.
Funtions : IP security
Increases Speed.
It performs IP verification as well as data scanning.
It have complete record of the IP visited by the User.
2-APPLICATION LEVEL-GATEWAY
(More secure than packet filtering)

17. PROXY SERVERs
11.22.33.44
11.22.33.44
22.33.44.55
PROXY SERVER IP
PRIVATE
PUBLIC
1- SECURE PRIVATE IP
(Generate proxy IP, it will be difficult to
guess original IP)

18. 2- CACHED WEB PAGE
(It makes web page retrieval easy & speedy
without involving public network.)
PROXY
SERVER
DATABASE
PRIVATE
FIRST REQUEST
INTERNET
SECOND REQUEST
R1
R2

19. From 1989-1990 three colleagues from AT&T Bell
Laboratories- Dave Presetto , Janardan Sharma, and Kshitij
Nigam, developed the third generation of firewalls, calling
them Circuit Level Firewalls
It is operate on Session level , monitoring TCP
handshakes( THREE WAY HANDSHAKES).
Instead of data packets it takes session level first.
Once the legitimate session is build then packets are
transferred.
3- Stateful Multilayer Inspection

20. THREE WAY HANDSHAKE
A client- sever communication session, where client initiates
the conversation by sending request to server side.
SYN (Synchronize)
Used to initiate & establishes a connection .
It also helps you synchronize the sequence number between
the devices.
It send a sequence number through which it will connect.
ACK(acknowledgement)
Helps to confirm the other side that it has received the SYN
packet.

21. TCP HANDSHAKING
A B
SOURCE DESTINATION
SYN-1
ACK-0
S.NO-2000
(Initial s.no of A)
SYN-1 ACK-1
ACK.no-(2000+1)2001
(next expected s.no from A )
S.NO-5000
(Initial s.no of B)
SYN-0 ACK-1
ACK.no-5001
(next expected s.no
from B)
S.NO-2001

22. ADVANTAGES OF FIREWALL
Focus for security decisions
Stop hackers from accessing your computer
Can enforce security policy
Protects your personal information
Limits your exposure
Blocks “pop up” ads and certain cookies
Can log Internet activity efficiently
Determines which programs can access the Internet

23. DISADVANTAGES OF FIREWALL
Can't protect you against viruses it needs anti-
virus for that purpose.
example- Norton , MacAfee provide complete
protection.
Can't protect against viruses ,worms and
spyware which spread through potable hard
disk , pen drive etc.
The good ones are expensive to buy , maintain.
examples-AVIRA,INTEGO,BIT DEFENDER.
It slows the internet access.

24. CONCLUSION
One of the best things about a firewall from a security
standpoint is that it stops anyone on the outside from logging
onto a computer in your private network.
A good firewall software must be able to provide complete
protection without sacrificing the speed of your computer and
your network access.
The more lines of defense you have in place ,the harder it
is for hackers to get in and the safer you will.

25. REFERANCES
https://www.ukessays.com/essays/computer-science/firewall-computer-science-
essays.php
https://personalfirewall.comodo.com/what-is-firewall.html
https://www.inetdaemon.com/tutorials/internet/tcp/3-way_handshake.shtml
https://www.excitingip.com/205/what-are-packet-filtering-circuit-level-inspection-
firewalls/

26. THANKYOU