ccna dis1 - chapter 8 - basic security [compatibility mode]

8/3/2019 CCNA Dis1 - Chapter 8 - Basic Security [Compatibility Mode]

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Chapter 8 Basic Security

CCNA Discovery 4.0

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Objectives

Identify and describe the various networking threats. Identify different methods of attack. Describe security procedures and applications. Describe the features of a firewall and how it can be used

to protect against an attack.

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Networking Threats

Risk of Network Intrusion



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Networking Threats

Sources of Network Intrusion



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Networking Threats

Social Engineering and Phishing



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Networking Threats

Social Engineering and Phishing



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Methods of Attack

Viruses, Worms and Trojan HorsesViruses Worm Trojan Horses

A virus is aprogram that runsand spreads by

modifying otherprograms or files

A virus cannotstart by itself; itneeds to beactivated

Viruses can betransmitted viaemail attachments,downloaded files,instant messagesor via diskette, CDor USB devices

Worm does notneed to attach itselfto an existing

programA worm uses thenetwork to sendcopies of itself toany connectedhosts

Worms can runindependently andspread quickly

A Trojan horse isa non-selfreplicating program

that is written toappear like alegitimate program,when in fact it is anattack tool

Trojans can also

create a back doorinto a systemallowing hackers togain access



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Methods of Attack

Denial of Service and Brute Force Attacks



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Methods of Attack

Spyware, Tracking Cookies, Adware and Pop-upsSpyware Tracking Cookies Adware Pop-ups

Spyware is anyprogram thatgathers personalinformation from

your computerwithout yourpermission orknowledge

Spyware is usuallyinstalled

unknowingly whendownloading a file,installing anotherprogram or clickinga popup

Difficult to remove

Cookies are aform of spyware butare not always bad

They are used to

record informationabout an Internetuser when they visitwebsites

Many web sitesrequire that cookies

be enabled in orderto allow the user toconnect.

Adware is a formof spyware used tocollect informationabout a user based

on websites the uservisits

Adware iscommonly installedby a user inexchange for a

"free" productAdware can bevery difficult touninstall

Pop-ups and pop-unders areadditionaladvertising windows

that display whenvisiting a web site

pop-ups and pop-unders are notintended to collectinformation about

the userPop-ups: open infront of the currentbrowser window.

Pop-unders: openbehind the currentbrowser window.



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Methods of Attack

Spam



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Security Policy

Common Security Measures



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Security Policy

Common Security MeasuresDescribe common security procedures



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Security Policy

Updates and PatchesDescribe how updates and patches relate to security issues.



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Security Policy

Anti-virus software features: Email checking - Scans incoming andoutgoing emails, and identifies suspicious

attachments.

Resident dynamic scanning - Checks

executable files and documents whenthey are accessed.

Scheduled scans - Virus scans can bescheduled to run at regular intervals

and check specific drives or the entire

computer.

Automatic Updates - Checks for, anddownloads, known virus characteristics

and patterns. Can be scheduled to check

or updates on a regular basis.



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Security Policy

Anti Spam



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Security Policy

Anti-Spyware



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Using Firewalls

What is Firewall Appliance-based firewalls - An appliance-based firewall is a firewall that is built-in

to a dedicated hardware device known as

a security appliance

Server-based firewalls - A server-basedfirewall consists of a firewall applicationthat runs on a network operating system

(NOS) such as UNIX, Windows or Novell

Integrated Firewalls - An integratedfirewall is implemented by adding

firewall functionality to an existing device,

such as a router

Personal firewalls - Personal firewallsreside on host computers and are not

designed for LAN implementations



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Using Firewalls

Using a Firewall to Protect Against an Attack



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Using Firewalls

Vulnerability Analysis



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Using Firewalls

Best Practices



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Summary

Networks can be open to intrusion through vulnerabilities insoftware, hardware attacks, or the weaknesses ofindividuals.

Effective network security is based on a variety of productsand services, combined with a thorough security policy.

A firewall controls traffic between networks and helpsprevent unauthorized access.



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