WEL COME

FIREWALL

Presented By:-

Rameswar Mishra,

1151017007

Guided By-Ms.

Rosalin Mahapatra,

Dept. of CS&IT.

Contents What is firewalls. Hardware vs softwares firewalls. Firewall Rules How does Software firewall work What a firewall can’t protect against Packet level filter Proxy server Conclusion Reference

What is a Firewall?

• A firewall is 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

Hardware vs. Software Firewalls

• Hardware Firewalls

– Protect an entire network

– Implemented on the router level

– Usually more expensive, harder to configure

• Software Firewalls

– Protect a single computer

– Usually less expensive, easier to configure

Firewall Rules

• Allow

• Block

• Ask

How does a software firewall work?

• Inspects each individual “packet” of data as it arrives at either side of the firewall

• Determines whether it should be allowed to pass through or if it should be blocked

What a Firewall Cannot Protect Against

• Trojan horse

• Social engineering

• Physical outrages

Packet-level filter

A category of firewall that provides a high

degree of convenience, but a relatively low level of

security. A packet-level filter blocks or forwards a packet

solely on its merits, without taking into account past

history; the filter may also look at the source and

destination address information contained in the packet.

Application-level filter

A category of firewall that provides a

high degree of security but at the cost of lower

speed and greater complexity.

Typical application-level filters can

provide proxy services for applications and

protocols such as Telnet, FTP and HTTP

Proxy server

• proxy server is a computer that offers a computer

network service to allow clients to make indirect

network connections to other network services.

• A proxy server can also serve as a firewall.

How Proxy Server Works

Windows XP Firewall

• Enable under Start -> Settings -> Control Panel

• Select Local Area Connection• Select the Properties button• Click the “Advanced” tab

Windows XP firewall

Conclusion

A firewall is a necessity if you are going to connect your

LAN to the Internet. Firewalls can examine the traffic coming into

and going out of your LAN and make decisions on what kinds of

traffic to permit or deny .

• Ingham, Kenneth; Forrest, Stephanie (2002). "A History and Survey of Network Firewalls

• http://www.wanredundancy.org/resources/firewall/network-layer-firewall

THANK YOU