firewall itam
TRANSCRIPT
8/4/2019 Firewall ITAM
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Brief History
The idea came from constructionindustry in 19th century.
•Structure of metal sheets in
houses, flights etc were the first
physical firewall.
•Metal sheets protected from fire.
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People who made it important.
Clifford Stoll a US astronomer and
computer expert, discovered that
German spies accessing his system .
After this incident US started to
implement firewall security in the
government networks.
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Bill Cheswick the author of the
famous security book “Firewalls and
Internet Security ” set up a simpleelectronic jail to observe an attacker.
He devoted himself and brought a
huge impact on awareness of firewall
and internet and network security.
People who made it important.
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Robert Tappan Morris created Morris Worm
which was the virus that awakened all the
network administrators and made themthink of the importance of firewall. The
networks administrators weren’t expecting
anything like this. The worm spread around
networks around the world. 10% of the
internet was infected.
People who made it important.
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What is a Firewall?
• A firewall is hardware,
software, or a combination of
both that is used to prevent
unauthorized programs orInternet users from accessing a
private network and/or a
single computer.
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What do Firewalls Protect?
• Data – Proprietary corporate information
– Financial information
– Sensitive employee or customer data
• Resources – Computing resources
– Time resources
• Reputation – Loss of confidence in an organization
– Intruder uses an organization’s networkto attack other sites
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Who do Firewalls Guard
Against?
• Internal Users
•
Hackers
• CorporateEspionage
• Terrorists
• Common
Thieves
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Classification of Firewall
Characterized by protocol level itcontrols in
• Packet filtering
•
Circuit gateways• Application gateways
Combination of above is dynamic
packet filter.
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Firewalls – Packet Filters
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• Simplest of components• Uses transport-layer information only
– IP Source Address, Destination Address
– Protocol/Next Header (TCP, UDP, ICMP, etc) – TCP or UDP source & destination ports
– TCP Flags (SYN, ACK, FIN, RST, PSH, etc)
–ICMP message type
• Examples
– DNS uses port 53
•
No incoming port 53 packets except known trusted servers
Firewalls – Packet Filters
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Firewall Gateways
• Firewall runs set of proxy programs
– Proxies filter incoming, outgoing packets
– All incoming traffic directed to firewall
– All outgoing traffic appears to come from firewall
• Policy embedded in proxy programs
• Two kinds of proxies
– Application-level gateways/proxies
• Tailored to http, ftp, smtp, etc.
– Circuit-level gateways/proxies
• Working on TCP level
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Firewalls - Circuit Level
Gateway
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Basic Firewall Components
• Software
• Hardware
• Purpose Built/Appliance
based
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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
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Some Known Hardware
FirewallsD-Link: D-Link DIR-655 Xtreme N
Gigabit Router
•Has fast performance.
•
A combination of latest in builtwireless security and intergraded
wireless security wizard is used.
Controlled very easily.
Some Known Hardware
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• Cisco: ASA 5550 Firewall – Delivers advanced threat defense
service.
–
Network and application trafficwill be protected.
– Defensive from worms, virus and
network attacks such as denial of
services or DDOS.
– Spyware and adware protection.
Some Known Hardware
Firewalls
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How does a software firewall
work?
• Inspects each individual
“packet” of data as it arrives at
either side of the firewall
• Inbound to or outbound from
your computer
• Determines whether it shouldbe allowed to pass through or if
it should be blocked
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Firewall Rules
• Allow – traffic that flowsautomatically because it has been
deemed as “safe”.
• Block – traffic that is blocked becauseit has been deemed dangerous to
your computer
• Ask – asks the user whether or notthe traffic is allowed to pass through
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Some Known Software Firewalls
• Kaspersky Internet Security: – Provides a comprehensive
security tool kit.
–
A nicely organized interface. – Protects from malware, dos
attacks etc. Has a powerful
firewall.
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• Norton 360: – Has the best value for easy use
of tools offered, and
overall system performance. – Uses multiple tools to control
the firewall.
Some Known Software Firewalls
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Some Known Software Firewalls
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What a personal firewall can
do?
• Stop hackers from accessing
your computer
• Protects your personal
information
• Blocks “pop up” ads and certai
cookies
• Determines which programs
can access the Internet
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What a personal firewall
cannot do??
• Cannot prevent e-mail viruses
– Only an antivirus product with
updated definitions can prevent
e-mail viruses
• After setting it initially, you
can forget about it
– The firewall will require periodic
updates to the rulesets and the
software itself
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Examples of personal firewall
software• ZoneAlarm <www.zonelabs.com>
• BlackICE Defender <http://blackice.iss.net>
• Tiny Personal Firewall <www.tinysoftware.co
• Norton Personal Firewall www.symantec.com
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Windows XP firewall
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Mac OS X firewall
• *Not* enabled by default
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Windows Firewall
Windows Firewall helps protecting
your computer by preventing
unauthorized users from gaining
access to your computer through anetwork or internet.
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What does it do??
• Help block computer viruses
and worms from reaching your
computer.• Ask for your permission to
block or unblock certain
connection requests.• Create a record (a security log)
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Router Firewall
Hardware firewall
Difference between Hardware firewall anD Software firewall:
– Configuring for maximum security – Strengthening Home router firewalls
Block 'stealth' mode :
– Disable remote administration
Attack detection : – Disable file and printer sharing
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Firewall in Business
Organizations
Security
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Other than the mentioned benefits,
firewall installation offers many other
benefits.
One of the most important is the blocking
of useless web pages, saving the
resources of the organization and time of
the employees.
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Other benefits of a
firewall in the office
include themonitoring of an
employees usage of
the system.
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Providing the
organization,
just what isimportant for its
functioning andno crap.
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Reducing Distractions
due to unproductiveactivities on the
internet.
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