firewall presentation with all types of firewall and pros and cons.

1. PRESENTATION
ON
FIREWALL
Submitted by:
Gaurav Rajput
15-CAB-17

2. Contents :
 Introduction.
 What is an attack
 Hardware Firewalls
 Software Firewalls
 Firewall rules
 Types of Firewall techniques
 What a personal firewall can do
 What a personal firewall cannot do
 Conclusion

3. Introduction
A firewall is a device (or software feature) designed to
control the flow of traffic into and out-of a network.
 It is used to prevent unauthorized programs or Internet
users from accessing a private network

4. It monitors and controls the incoming and outgoing
network traffic based on predetermined security
rules.
In general, firewalls are installed to prevent
attacks.

5. What is an Attack?
Attack covers many things:
1. Someone probing a network for computers.
2. Someone attempting to crash services on a
computer.
3. Someone attempting to crash a computer.
4. Someone attempting to gain access to a computer
to use resources or information.

6. Hardware Vs Software Firewalls
Hardware firewalls
o Implemented on router level.
o Protect an entire network.
o Usually more expensive, harder to implement.
Software firewalls
o Protects a single computer.
o Usually less expensive, easier to implement.

7. Hardware Firewalls
Hardware firewalls are used more in companies and large
corporations.
 These devices are usually placed between the router and
the Internet connection.
A hardware firewall uses packet filtering to examine the
header of a packet to determine its source and destination.
 This information is compared to a set of predefined or
user-created rules that determine whether the packet is to
be forwarded or dropped.

8. Software Firewalls
For individual home users, the most popular firewall choice
is a software firewall. Software firewalls are installed on
your computer (like any software).
We can customize it; allowing us some control over its
function and protection features.
It protect our computer from outside attempts to control or
gain access our computer.
It also provide protection against the most common Trojan
programs or e-mail worms.

9. Inspects each individual “packet” of data as it arrives
either side of firewall.
Determines if it should me pass through or blocked.

10. Types of firewall technique
1. Packet filtering firewall
2. Application proxy firewall
3. Stateful inspection firewall
4. Circuit – level gateway firewall

11. Packet filtering firewall
A packet filtering firewall applies a set of rules to each
incoming and outgoing IP packet and then forwards or
discards the packet.
Filtering rules are based on information contained in
network packet.
 Sources IP address
 Destination IP address
 Sources and destination transport level address
 IP protocol field
 Interface

12. Packet filtering firewall
Two default policies are there to take default action to
determine whether to forward or discard the packet.
 Some possible attacks on firewall :
 Default = discard
 Default = forward
 IP address spoofing
 Source routing attacks
 Tiny fragment attacks

13. Packet filtering firewall
Advantage :
Disadvantage :
 Cost
 Low resource usage
 Best suited for smaller network
 Can work only on the network layer
 Do not support complex rule based support
 Vulnerable to spoofing

14. Application Proxy Firewall
An application – level gateway, also called an application
proxy , acts as a rely of application – level traffic.
It don’t allow any packets to directly pass between an
application and the user.
User requests service from proxy.
Proxy validates requests as legal.
Then actions requests and returns result to user.
Can log / audit traffic at application level.

15. Application Proxy Firewall
Advantages :
Disadvantages :
 More secure than packet filter firewalls.
 Easy to log and audit incoming traffic.
 Additional processing overhead on each connections.

16. Stateful Inspection firewall
A stateful inspection packet firewall tightens up the rules
for TCP traffic by creating a directory of outbound TCP
connections.
There is an entry for each currently established
connections.
The packet filter now allow incoming traffic to high –
numbered ports only for those packets that fit the profile
of one of the entries in this directory.
A stateful packet inspection firewall reviews the same
packet information as a packet filtering firewall , but also
records information about TCP connections.

17. Stateful Inspection firewall
It records session information such as IP addresses and
port numbers, which implement a much tighter security
posture than a static packet filter firewall.
It examines both incoming and outgoing packets

18. Circuit – level gateway Firewall
 This can be a stand – alone system or it can be a specialized
functions performed by an application – level gateway for certain
applications.
 It does not permit an end – to – end TCP connection; rather , the
gateways sets two TCP connections.
 A typical use of the circuit – level gateways is a situation in which
the system administrator trusts the internal users.
 The gateways can be configured to support application – level or
proxy service on inbound connections and circuit- level functions
for outbound connections.

19. Circuit – level gateway Firewall
Advantage :
Disadvantage:
 Comparatively inexpensive and provide Anonymity to the
private network.
 Do not filter individual Packets.

20. What a personal Firewall can do
Stop hackers from accessing your computer.
Protect your personal information.
Blocks “pop up” ads and certain cookies.
Determine which program can access the internet.
Blocks invalid packets.

21. What a personal Firewall can not do
Cannot prevent e-mail viruses.
only an antivirus product with update
definitions can prevent e-mail viruses.
 After seeing it initially, you cannot forget about it.
The firewall will require periodic updates
to the set rules and the software itself.

22. Conclusion
It is clear that some form of security for private networks
connected to the internet is essential.
A firewall is an important and necessary part of that
security , but cannot be expected to perform all the
required security functions

23. THANK YOU