Maintaining the Network

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Hot and Cold Spares  Hot spare requires no technician intervention Hot spare  Cold spare requires technician to install it into the system after removing the failed component Cold spare

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Hot, Cold, and Warm Sites  Describes the readiness of an off-site data storage facility to recover from a failure at the primary site

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Electrical Surge  Can be suppressed by a lightening arrestor or an Uninterruptible Power Supply (UPS)lightening arrestor

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Electrical Spike  Can be caused by electrical equipment, such as motors, welders, and switches  The result of inductive reactance, which is associated with the coils inside some electrical equipment  Isolating the computer system electrical circuit can reduce the effects

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Brownout  Main cause is excessive consumption of electricity  Can damage electrical equipment  UPS unit could prevent its effects

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Blackout  Routinely caused by electrical system equipment failure  Can cause a loss of data  UPS unit could prevent its effects

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Uninterruptable Power Supply (UPS)  Protects against electrical surges, spikes, brownouts, and blackouts  Exact length of time UPS can supply power during a blackout depends on the:  Amount of electrical load it must support  Size or amp-hour capacity of the batteries in the UPS unit  Provides power conditioningpower conditioning

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. UPS Categories  Standby UPS—Still possibility of data corruption Standby UPS  Continuous UPS—Eliminates possibility of data corruption Continuous UPS  Isolation transformer—Normally used to raise or lower voltage levels in electrical systems Isolation transformer  A generator should be used for computer systems that require 24/7/365 uptimegenerator

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Protecting Networks from Malware  Malicious code can compromise security, damage data, and cause system failure  Best protection against malware is a combination of:  User policies  Antivirus software

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. User Policies  Outline how users are to use and not use their workstation and the network  Should be set in place and enforced  Typically called an Acceptable Use Policy

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Acceptable Use Policy  Do not open attachments from unknown sources, or with exe, com, or bat extensions  Do not download any files from unknown sources  Update antivirus software on a regular basis  Never open ads, chain letters, or junk mail  Do not click icons embedded in files or s  If you doubt authenticity, verify source first

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Antivirus Software  Used to scan files and for viruses  Should be installed on server and each workstation  Consists of a scan engine and a virus pattern filescan enginevirus pattern file  Virus pattern file should be updated on regular basis  Antivirus suite can include firewall, spam protection and popup ad blocker Antivirus suite

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Malware  Contraction of description malicious software  Unauthorized activity can be harmless or destructive  The terms malware, virus, and worm are often used interchangeably; this is not technically correct  Can be a combination of classifications

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Virus InfectionReplicationExecution Three Phases of a Virus

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Worm  Different than a virus in that it spreads to network computers from the infected computer  Is typically distributed through

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Trojan Horse  Once it is opened, the malware is activated  Can cause immediate damage or wait until preset date  Has harmless outward appearance  Can cause most anything imaginable to the computer

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. A user receives an posing to be from the IRS. Attached is a document with malicious code. When the attachment is opened, the code executes, steals banking information stored on the user’s computer, and forwards it to the malicious party. How would this type of virus be classified and why? Applied Networking

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. A user receives an posing as a Facebook notification. The prompts the user to click a URL to view the message. When the user clicks the URL, he or she is taken to a site and prompted to install a fake Facebook Messenger program. This program, if installed, allows an intruder to execute any command from the user’s computer. How would this type of virus be classified and why? Applied Networking

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Joke Program  Typically activated when the user invokes a certain action  Some jokes are not destructive, but time is needed to remove program  Examples: A dialog box indicating the hard disk drive is about to be formatted

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. MBR Virus  Plants a hexadecimal code in the master boot record, rendering the MBR useless  Results in boot failure  Many antivirus programs perform MBR backups as part of their installation

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Logic Bomb  Can be triggered by a date, time, certain number, word, file name, etc.  In waiting before delivering its payload, this malware has time to spread to other computers

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Backdoor Virus  Not designed to be directly destructive, but to breach security systems  Backdoor allows computer file system to be accessed by an intruder

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Password Virus  Steals a password and stores it on another location  Is closely associated with the backdoor virus and may be used in combination

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Stealth Virus  Signature of a stealth virus is difficult to detect  Antivirus program detects stealth virus by changes to file length

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Polymorphic Virus  Changes its characteristics to go undetected by antivirus programs  Most dangerous viruses use both polymorphic and stealth characteristics

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Hoax  Can be classified as a prank  Can cost money through loss of production  Consumes a lot of time to determine that program is harmless

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Macro Virus  Created with the macro feature of a software applicationmacro  Usually distributed as an attachment

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. System Migration  Can refer to:  Combining two diverse network systems  Converting an operating system to a newer version that uses different technologies

I N CLASS LAB Roberts Labs 84,85 N EXT C LASS LabSim homework: