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• Computer and network security help keep data and equipment safe by giving only the appropriate people access
• Everyone in an organization should give high priority to security, because everyone can be affected by a lapse in security
• Theft, loss, network intrusion, and physical damage are some of the ways a network or computer can be harmed
• Technician's primary responsibilities


  • Data and network security
  • Repair, adjust, and install equipment
  • Configure settings to keep the network secure, but still keep it available to those who need to access it
  • Ensure that software patches and updates are applied, antivirus software is installed, and antispyware software is used
  • Instruct users on how to maintain good security practices with computer equipment
• Physical security attacks


  Events or attacks that steal, damage, or destroy such equipment as servers, switches, and wiring
• Data security attacks


  Events or attacks that remove, corrupt, deny access to, allow access to, or steal information
• Potential threats


  • Internal (Malicious threats, Accidental threats)
  • External (Unstructured attacks, Structured attacks)
• Virus


  Attached to small pieces of computer code, software, or document, and executes when the software runs on a computer
• Worm


  Self-replicating program that is harmful to networks, uses the network to duplicate its code to the hosts on a network, often without any user intervention
• Trojan horse


  Does not need to be attached to other software, hidden in software that appears to do one thing, and yet behind the scenes it does another
• Antivirus software


  Software designed to detect, disable, and remove viruses, worms, and Trojans before they infect a computer
• Commonly used antivirus


  • Norton, Kaspersky, Eset, Mcafee, Trend Micro, Avast, Avira, AVG and SmadAV
• SmadAV antivirus


  • Works with any other antivirus software
  • Very lightweight and takes low resource to run
  • Best USB protection to stop spreading virus through USB flush drive
  • Cleans infected computer and fix the registry changed by the viruses
  • Adds new viruses in the SmadAV database regularly and keep protected
  • Updates automatically with the new versions of SmadAV (Pro-version)

  
• How to download and install SmadAV


  1. Access http://www.smadav.net/ website and click on Free Download

  2. Wait till save as window appears, save the file on the Desktop

  3. Double click on the file from the desktop

  4. Click OK with language selection (English)

  5. Click Next on the Welcome Wizard

  6. Accept the license agreement and click Next

  7. Click Next with Desktop shortcut option

  8. Click Install

  9. Click Launch and Finish

  
• Firewall


  Security feature that establishes a barrier or an invisible wall from trusted or untrusted network, acts as the first line of computer's defense aside from Anti-Virus, decides whether to allow or block specific traffic based on a defined set of security rules
• Turning on your computer's firewall


  Click Start Button, Click Control Panel, Click System and Security, Click Windows Firewall, Turn on your Firewall Settings

  
• IP address


  Combination of network address and host address
• Subnet mask


  Determines how many bits are used in network address and how many bits are left for host address
• IP address classes


  • Class A, Class B, Class C, Class D, Class E
• There are 4,294,967,296 IP addresses
• Reserved IP addresses


  • 0.0.0.0, 127.0.0.0 to 127.255.255.255, 224.0.0.0 to 239.255.255.255, 240.0.0.0 to 255.255.255.254, 255.255.255.255
• Network address


  IP address with all host bits turned off
• Host address


  Part of IP address where we can turn on and off bits
• Private IP addresses


  10.0.0.0 to 10.255.255.255, 172.16.0.0 to 172.31.255.255, 192.168.0.0 to 192.168.255.255
• Public IP addresses


  All remaining IP addresses of Class A, B and C not defined as private IP addresses
• Unicast address


  Represents an individual end device
• Multicast address


  Represents a group of devices
• Broadcast address


  Represents all devices of the network
• Messages sent on a multicast address are normally allowed to pass through the router, while messages sent on a broadcast address are not allowed to pass through the router under any circumstances