Fire-wall

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Fire-wall
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Outlines

• Firewall concept.
• Fire-wall rule.
• Types of fire-wall.
• How fire-wall works?
• Using more than one firewall on a computer.
• Fire-wall vs. Antivirus.
• SUMMARY.

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What is firewall?

• A firewall is software or hardware that checks
  information coming from the Internet or a
  network, and then either blocks it or allows it
  to pass through to your computer, depending on
  your firewall settings.

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Why do I need a fire-wall ?

• A firewall can help prevent hackers or malicious
  software (such as worms) from gaining access to
  your computer through a network or the Internet.
  A firewall can also help stop your computer from
  sending malicious software to other computers.

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Why do I need a fire-wall ?..(cont)

• Even if you think there is nothing on your
  computer that would interest anyone, a worm could
  completely disable your computer, or someone
  could use your computer to help spread worms or
  viruses to other computers without your
  knowledge.

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Is their another things fire-wall can't
prevent?

• YES, They are
• 1- E-mail viruses .
• 2- Phishing scams .

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Types of fire-wall

• 1- personal firewall
• In the home, a personal firewall typically comes
  with or is installed in the user's computer .
• Personal firewalls may also detect outbound
  traffic to guard against spyware, which could be
  sending your surfing habits to a Web site.

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2-Organization fire-wall

• In the organization, a firewall can be
• a stand-alone machine.
• software in a router
• server.
• Combination of routers servers.

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Can I use more than one firewall on my computer?

• Yes, but running more than one firewall program
  at the same time could cause conflicts.
• It's best to just use one firewall program.

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How fire-wall work??

• Firewalls use one or more of three methods to
  control traffic flowing in and out of the
  network
• Packet filtering.
• Proxy service.
• Stateful inspection.

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Packets filtering

• Packets (small chunks of data) are analyzed
  against a set of filters. Packets that make it
  through the filters are sent to the requesting
  system and all others are discarded.

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Proxy service

• Information from the Internet is retrieved by the
  firewall and then sent to the requesting system
  and vice versa.

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Stateful inspection

• - A newer method that doesn't examine the
  contents of each packet but instead compares
  certain key parts of the packet to a database of
  trusted information. Information traveling from
  inside the firewall to the outside is monitored
  for specific defining characteristics, then
  incoming information is compared to these
  characteristics. If the comparison yields a
  reasonable match, the information is allowed
  through. Otherwise it is discarded.

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Fire-wall vs. antivirus

• Firewall protection will stop hackers from
  getting into your computer or network, and so
  will stop viruses as well.
• Antivirus software protects computers from
  viruses and other malware, such as Trojans, worms
  and keyloggers. However you can pick up a virus
  in different ways such as from a CD or USB, from
  another computer on the network, etc

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Summary

• Firewall is a piece of software that creates a
  barrier between Internet and your PC.
• Fire-wall control the traffic that goes from and
  to your computer and blocks such packets.
• Personal organization fire-wall.
• One fire-wall software is enough in PC.
• Antivirus work with viruses fire-wall control
  the traffic.

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Reference

• A History and Survey of Network Firewalls
• KENNETH INGHAM
• Kenneth Ingham Consulting
• and
• STEPHANIE FORREST
• www. ITSecurtiy.com

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• Thanks