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Module 1 Computer hardware, chapter 1, 2, 3, 8 KLART!!! Electrical safety Electrical devices have certain power requirements, AC adapters are made for specific laptops Switching the adapter with another type of computer may damage both laptop and adapter Electrostatic discharge May occur during bui...

Module 1 Computer hardware, chapter 1, 2, 3, 8 KLART!!! Electrical safety Electrical devices have certain power requirements, AC adapters are made for specific laptops Switching the adapter with another type of computer may damage both laptop and adapter Electrostatic discharge May occur during buildup of electric charge on a surface which comes in contact with another differently charged surface To prevent ESD Keep components in antistatic bags up until use Use grounded mats on your workbench Use grounded floor mats in work areas Use antistatic wristband when working inside computers PC components Power supply Concert AC power into lover voltage DC power for internal components, Comes with a basic cooling fan. PSU provides voltages 3.3v 5v (digital circuits) and 12v (running motors in disks and fans). Comes in several different Form factors AT - Original PSU, used in the first computers today it is obsolete Atx - Upgraded version of AT also obsolete Atx12v - Most common PSU on today’s market, provides extra power to the CPU via its second motherboard slot Eps12v - Originally for high end desktop models. Connectors PSU includes different connectors that are used to power various internal components, such as motherboard and disk drives. These connectors are keyed. SATA connector comes in 20 and 24 pin and used to power disk drives Auxiliary power connector comes in 4 and 8 pin, and supplies power to different areas of the motherboard. Motherboard The backbone of the computer. It consists of electrical pathways which interconnects the internal components, for instance SATA, auxiliary power It consists of CPU Pci slots Random Access memory Internal usb connectors Sata connectors BIOS/UEFI Motherboard form factors Atx - Most common one, the PSU connects to the motherboard via a 20 pin sata connector Micro atx - Backwards compatible with the ATX, can often use the same chipset and power connectors as the ATX, as well as the same components, however it does not provide the same amount of expansion slots due to its size ITX - Popular due to its small size, uses little power so there are no needs for fans to cool it, only offers one pci slot for expansion cards. It is useful in quiet environments. Central processing unit CPU Small microchip that resides within the CPU package. CPU is responsible for executing and interpreting commands. CPU socket A connection between the motherboard and the processor. Land grid array (LGA) Pins are on the underside of the CPU package that shall be inserted in the motherboard socket using ZIF Pin grid array (PGA) Pins are located on the CPU socket instead of on the processor. Cooling system A computer works best when kept cool, since internal components generate heat, the computer gets hot, and to high temperatures may crash or damage the components Passive cooling A cooling system that does not require power, for instance, heat shrinks that leads away the heat from a component directly to a fan. Or a method where the PC reduces the speed at which the components are operating at. Active cooling A cooling system that requires power to function, for instance, fans or water cooling systems. Chipset Consists of integrated circuits controlling how the system hardware interacts with the CPU and the motherboard Northbridge Controls high speed access to RAM and video card, it also controls at what speed the cpu communicates with other internal components. Southbridge Allows CPU to communicate with slower speed devices such as the hard drive, USB ports and expansion slots. Types of memory Read only memory (ROM) Located on the motherboard and consists of instructions which can be directly accessed by the CPU, such as booting the computer and loading the OS. ROM is non volatile meaning that when turning off the computer the content saved is not erased Random access memory (RAM) Temporary working storage for data and programs that are being accessed by the CPU. Unlike ROM this is volatile memory, meaning when turning off the computer the content is erased. Adding more RAM Enhances the computer performance by being able to hold and process more programs and files at the same time, rather than the CPU having to swap data between the RAM and a hard drive. Before adding more ram you need to make sure that the motherboard is compatible with the new amount of RAM Types of ROM Programmable ROM Manufactured blank and can be programmed by a PROM programmer when necessary, these chips cannot be erased and only programmed once Erasable PROM Non volatile, but can still be erased by exposing it to UV light. Constant erasing and reprogramming the chip would eventually render the chip useless. Electrically EPROM Information is written on the chip after it is manufactured, and without removing it from the device. Also known as flash ROM, since the content can be flashed for deletion. Typically used to store a computer system’s BIOS Types of RAM Dynamic RAM Used as main memory, this is what we refer to when talking about adding more RAM. It gradually discharges energy so it must be constantly refreshed with pulses of electricity in order to maintain the stored data. Static RAM Fastest type of RAM, used for cache memory which is stored in the CPU. Requires low power consumption but needs constant power to function Synchronous DRAM DRAM that operates synchronized with the memory bus, it is able to process overlapping instructions in parallel, for instance it can process a read before a write has been completed. Double Data Rate SDRAM Transfers data twice as fast as SDRAM, able to support two writes and two reads per CPU clock cycle. Has a single notch and 184 pins. DDR2 SDRAM Same transfer speed as DDR SDRAM, it has 240 pins connectors and improves performance by decreasing noise and crosstalk between signal wires. DDR3 SDRAM Expands memory bandwidth by doubling the clock rate of DDR2, it consumes less power along with less heat generated compared to DDR2. Clock speed up to 800MHz, connector has 240 pins. DDR4 SDRAM Quadruples memory DDR3 maximum storage capacity and consumers even less power and has a clock speed up to 1600MHz. 288 pin connector. It can come with advanced error correction features such as ECC, to detect multiple bit errors. Graphic DDR SDRAM Ram specific for video graphics, used in conjunction with a GPU, it processes massive amounts of data but not at the fastest speeds. DDR 5 More than double speed of the DDR4 modules, also quadruples its storage capacity. Maximum module size is 128 GB Memory Modules A memory chio is soldered to a circuit board which is what we call a memory module, which is placed into a memory slot on the motherboard Single Inline memory module (SIMM) Small circuit board holding several memory chips Dual inline memory module (DIMM) Holds SDRAM, DDR SDRAM, DDR2(3,4) SDRAM chips. ‘ Small outline DIMM (SODIMM) Smaller and condensed version of dimm, provides random access data storage that is commonly used in laptops, printerns and other devices where conserving space is desirable. Single sided double sided and multi channel memory modules Single sided memory module Standard RAM is single channel meaning that all slots are addressed at the same time, Double sided memory module Adds a second channel to be able to access a second module at the same time Triple channel technology Provides another channel so three modules can be accessed at the same time. This requires support from the chipset architecture, and only be able to use as many channels that have memory slots populated. Cache memory Sram is cache memory and it is storing the most recent used data and instructions by the CPU. SRAM provides CPU with faster access to data compared to DRAM or the main memory. Types of cache L1 cache Internal cache integrated to the CPU, different CPU models do offer different amounts of L1 cache L2 cache External cache, originally integrated on the motherboard close to the CPU, but nowadays integrated onto the CPU L3 Cache. Commonly used in high end workstations and server CPU. Adapter cards Increases functionality by adding controllers for specific devices into PCI slots on the motherboard, it can also replace damaged parts. Make sure that the adapter card matches the expansion slot Types of expansion slots PCI 32 and 64 bit expansion slots, today these are obsolete Mini PCI Usually found in laptops, comes in I, II and III PCI express Backwards compatible with 32 bit PCI devices. This is a serial point to point connection. comes in four lengths, x1, x4, x8 and x16. Where the number represents the number of data lanes Hard disk drives and Solid state drives Different types of storage devices, provide non volatile memory. HDD Traditional magnetic disk device, it storage ranges from GB to TB, speed is measured in Revolutions per minute RPM, indicating how fast a spindle inside turns the platters holding the data. SSD Stores data as electrical charges in semiconductor flash memory, makes it must faster than HDD since it has no moving parts, this also makes it more reliable than HDD since there are no moving parts that could fail. It ranges from 120GB to many TBs. It generates less heat and noise as well as being more energy efficient than HDD. If not coming as a disk it may come as an expansion card which is directly plugged into the motherboard and works like any other expansion card. mSATA or M.2 modules are also a form factor of the SSD. These packages use a special socket, M2 is a standard for computer expansion cards. Solid state hybrid drives (SSHD) Faster than HDD but less expensive than SSD, it combines a magnetic HDD with onboard flash memory serving as non volatile cache. It automatically caches data that is frequently used speeding up certain operations such as OS start up Input devices Allows us to communicate with the computer, for instance mouse and keyboard. Monitors LCD Two polarizing filters with liquid crystal solution between them, an electronic current aligns the crystals so light can pass/not pass through which creates the image. LED LCD display using LED backlightning, this has lower power consumption than LCD standard, the panel is thinner, lighter, brighter and better contrast than LCD OLED Type of lED display uses layers or organic material responds to electrical stimulus to emit light, the pixels light individually resulting in much deeper black levels than LED Printers Out device creating hard copies of files, for instance a sheet of paper, plastic form created by a 3d printer. Can be both wired and wireless, but all require printing material and a method to place it accurately on the paper or extrude it into a desired shape. Advanced computer hardware Boot the computer POST When a computer is booted, it performs a hardware check on the main components, Power on self test POST If device is malfunctioning, error or beep code alerts the technician of the problem. BIOS and motherboard manufacturers uses different beep codes for selected errors. Tip: Determine if POST is working correctly by removing ram modules, you should now get error message saying ram is not installed. BIOS and CMOS BIOS is necessary for motherboard to operate. The BIOS is a ROM chip containing small programs which controls communication between OS and hardware. BIOS also identifies, Available and bootable drives, How memory is configured and when it can be used, How PCIe and PCI expansion slots are configured. Motherboard BIOS settings They are saved in a CMOS memory chip When booted the bios reads configured settings stored in CMOS to determine how to configure the hardware. BIOS settings are stored in the CMOS CMOS Memory chip that stores the BIOS settings UEFI Provides additional features and addresses security issues with legacy BIOS. UEFI configures same settings as BIOS but also provide mouse enabled software instead of traditional BIOS screens. It can run on both 32 bit and 64 bit systems, it supports larger boot drives and secure boot Updated system for booting computers Secure boot Ensures computer boots to the specific OS, which prevents rootkits from taking over the systems. Prevents unauthorized OS from loading during startup UEFI standard that specifies the OS that is trusted by the manufacturer. BIOS/UEFI security Passwords Supervisor password, can access all bios screens and settings and user access passwords User password, can access bios on a defined level Drive encryption Hard drive can be encrypted to prevent data theft. Encryption changes data on a drive into code, and without correct passwords the computer cannot boot and data read from a drive cannot be understood. If drive is removed the data remains encrypted LoJack Locate, lock delete It consists of: Persistence module Embedded in BIOS Application agent, Has to be installed, and when done the PM in bios is activated and cannot be turned off, it routinely contacts monitoring center over the internet to report device information and location Trusted platform module (TPM) A chip Used to secure hardware by storing encryption keys, digital certificates, passwords and data. Used byBitlocker full disk encryption. Updating firmware Could come with security risk, Only update firmware if there are problems with the system hardware or to add functionality to the system Early computer BIOS Its information was contained in ROM chips, and to upgrade BIOS information you had to physically changed, which could be difficult. But modern BIOS chips are EEPROM meaning they can be upgraded by the user without opening the computer case, this process is called “Flashing the BIOS” Flashing the BIOS Updating an EEPROM boot chip without opening the computer. If installing new bios Consult the manufacturer's website and follow their recommended guidelines. But today most motherboards provide software to flash the BIOS from within an OS. An improperly installed or aborted BIOS update can cause the computer to become unusable Electrical power Wattage and voltage PSU specifications are typically expressed in watts (W). Ohm’s law Expresses how voltage is equal to the current multiplied by thee resistance: V=IR. In electrical system, power is equal to the voltage multiplied by the current. P=VI Voltage(V) Measure of work required to move a charge from one location to another Resistance (R) Refers to opposition to the flow of current in a circuit Current (I) This is a measure of the amount of electrons moving through a circuit per second Power (P) Measure of the work required to move electrons through a circuit, multiplied by the number electrons going through that circuit per second. PSU voltage settings Correct psu voltage settings determined by country psu is used in. Caution: Do not open a PSU, electronic capacitors located inside of a power supply can hold carhge for extended periods of time. Common voltages are 110/115v or 220v/230v Power fluctuation types When voltage in a computer is not accurate or steady, computer components might not operate correctly, unsteadyh voltages are called power fluctuations. Following AC power can cause data loss or hardware failure Blackout Complete loss of AC power, A blown fuse, damaged transformer or downed power line can cause a blackout Brownout Reduced voltage level of AC power that lasts for a period of time, occur when power line voltage drops below 80% of normal voltage level. Noise Interference from generators and lightning. results in poor quality power, causing errors in computer system. Spike Sudden increase in voltage lasting for a short period and exceeds 100 percent of the normal voltage on a line. Caused by lightning strikes. Power surge Dramatic increase in voltage above the normal flow of electrical current. Power protection device Use devices to protect the data and computer equipment Surge protector Helps protect against damage from surges/spikes, it diverts extra electrical voltage that is on the line to the ground. Amount of protection offered is measured by joules, when the amount of joules is reached, the surge protector no longer provides protection and needs to be replaced. Uninterruptible power supply (UPS) Protect against electrical power problems by supplying consistent level of electrical power to a computer or other device. Can communicate directly with the computer OS, and it allows the UPS to safely shut down the computer and save data prior to the UPS losing all battery power. Supplies a consistent level of electrical power to a computer or other device Standby power supply Provides backup battery to supply power when the incoming voltage drops below normal level. Battery is on standby during normal operation. When voltage decreases, the battery provides DC power to a power inverter which converts it into AC power for the computer. Not as reliable ass UPS because of the time it takes to switch over to the battery, and if the switch device fails the battery cannot supply power to the computer. Provides a backup battery to supply power when the incoming voltage drops below the normal Advanced computer functionality CPU architectures Program A sequence of stored instructions, a CPU executes these instructions by following a specific instruction set. Two distinct types of instruction sets CPUs may use Reduced instruction set computer (RISC) Uses small set of instructions, RISC chips are designed to execute these instructions rapidly. (PowerPC ARM) Complex instruction set computer (CISC) Uses broad set of instruction, resulting in fewer steps per operating. (intelx86 and motorola 68k) While CPU executes one step of the program, remaining instructions and data are stored nearby in high speed memory (cache memory) Enhancing CPU operation Power of CPU is measured by speed and amount of data it can process. amount of data it can process depends on size of the front side bus. Higher performance can be achieved when the width of the FSB increases, like a road can carry more cars when it has many lanes. CPU Hyperthreading Multiple pieces of code (threads) are executed simultaneously in the CPU. To the operating system a single CPU with hyperthreading performs as two CPUs when multiple threads are being processed. Hypertransport High speed connection between the CPU and northbridge chip CPU overclocking Make the CPU work faster than it is supposed to, not recommended since it can damage the CPU. opposite is CPU throttling CPU throttling Technique used when processor runs at less speed than its original to conserve power, or produce less heat, commonly used on laptops or mobile devices CPU virtualization Enables the processor to act as multiple processors, sometimes this could be disabled by default in BIOS settings and needs to be manually enabled. Multicore processors Incorporate more than one CPU core into a single chip. Multicore processors have two ro more processors on the same integrated circuit. between these two it is a very fast connection and they are able to execute instructions quicker than single core since the instructions can be distributed to all processors at the same time. They generate less heat and conserve power better than single core processors. Graphics processing unit Chip performing rapid mathematical calculations required to render graphics, can be both integrated and dedicated Dedicated Single chip with its own memory dedicated just for graphical processing, are more expensive but provide much better performance Integrated Dependent on system RAM, cheaper and generates less heat. Raid, redundant array of independent disks Provides a way to store data across multiple storage devices for availability, reliability, capacity, and redundancy/performance improvement. Raid concepts Striping Enables data to be distributed across multiple drives, failure of one drive means all data is lost Mirroring Stores duplicate data on one or more other drives, provides redundancy meaning failure of a drive does not cause loss of data. Parity Provides basic error checking and fault tolerance by storing checksums separately from data. Double parity Provides fault tolerance up to two failed drives. Raid levels There are different levels of raid available and they all provide different mixes of striping, parity mirroring and parity in different ways. Ports connectors and cables Legacy ports Computers offer different types of ports to connect computer peripheral devices. But is not used too much in new computes, have been replaced with USB ports i.e. Serial ports Used to connect printers, scanners, and modems. Today it is used for console connections. Parallell ports For peripheral devices. Parallel ports send data in multiple bits at once in parallel communication. Since they were often used to connect printers they are often called printer ports. Game ports Connector for joystick input. originally located on a dedicated game controller expansion card and later integrated with sound cards and on PC motherboards. PS/2 6 pin connector used for connecting keyboard and mouse. Purple for keyboard and green for mouse. Audio ports Connect audio devices to the computer. Analog ports typically include a line in port to connect to an external source. Vga Analog port, VGA are colored blue, 15 pin connector DVI Transmitting uncompressed digital video, yellow HDMI. Carries information as dVI but also prfoviding audio and control signals. HDMI is capable of high resolution. Comes in HDMI A, C and D Displayport Designed to replace a DVI and VGA, for connecting monitors. 20 pin, delivering high bandwidth video and audio signals like hdmi. Twisted pair cables and connectors Used in ethernet works, inside the cable the pairs of wires are twisted together RJ-45 connector Used to connect ethernet networks. Twisted pairs Untwisted pair (UTP) and Shielded twisted pair (STP). Computer configuration Motherboard upgrades Other components math have to change as well, such as CPU, heat sink and fan assembly, and RAM, the new motherboard must also be compatible with the old case and PSU must support it. Before upgrading make sure to document everything, the cables and so on to make sure everything is put back into its correct place. CPU upgrade Increasing processing speed increases the power of the computer. Better CPU results in improved computer performance. CPU must fit into existing CPU socket CPU must be compaitlbe with motherboard chipset CPU must operate with the existing motherboard and PSU Storage device upgrade Adding a hard drive is an option to buying a new computer which is faster and has more storage space. Increase storage space and hard drive speed Provides fault tolerance Back up original drive PSU Upgrade A computer can have two PSU, one acts a redundant psu in case of failure. it allows both psu to be hot swappable Protecting the environment Safe disposal methods Make sure to follow regulations on how to dispose specific items. Batteries Rare earth metals bad for environment. Dispose according to local regulations Monitors High voltage can be stored in monitors even after being disconnected. Dispose according to local regulations Toner kits, cartridges and developers. Dispose according to local regulations. Some cartridges allow them to be refilling. Safety data sheets Fact sheet with info about material identification. Provides protective measures for sage handling and storage of materials and spill, leak and disposal procedures. Helps you determine whether a material is classified as hazardous. Explains how to dispose of potentially hazardous materials in the safest manner. Printers Inkjet printer, impact printer, 3D printer, thermal printer, laser printer Printer speed, quality, and color Speed and quality Speed is affected by complexity of image and quality desired by the user. Quality is measured in dots per inch. The higher DPI number equals better image resolution. To produce best high resolution images, use high quality ink or toner and high quality paper. Color Primary colors used are cyan, magenta and yellow. Reliability and total cost of ownership Warranty Scheduled servicing Mean time between failures.. Think if the total cost of ownership (TCO) when buying a printer, price per page, pager per month, warranty costs, maintenance costs, initial purchase price Automatic document feeder and network scanning Automatic document feeder (ADF) A slot where existing document can be placed, the machine then makes copies of the wanted document It pulls one page onto the glass surface on the platen, it is scanned and copies are made. Printer connection types A printer must have a compatible interface with the computer to print. Often connected using a USB or wireless interface. Serial connection Parallel connection USB connection Firewire Ethernet Network scanning Scan to cloud Scan is uploaded to a storage location in the cloud. Multi function devices (MFD) may have specific cloud locations that are pre configured. Scan to folder Scan is sent to a network folder on the LAN. Scan to email Scan will be created as a file attachment in an email. Printer type comparison Inkjet printers Easily used, low cost and high resolution and quick to warm up. But prone to clogging, and the ink is wet for a few seconds after printing. Inkjet printer parts Print head Located on the carriage, which is attached to a belt and motor Nozzles Tiny holes in the print head Ink cartridges Inkjet printer use these to spray ink onto a page Piezoelectric crystals A charge is applied to cause the crystals to vibrate, which controls the flow of ink onto the paper. Located at the back of each nozzle Thermal Heat creates a bubble of steam in the chamber, steam forces ink out thorugh the nozzle and onto the paper Duplexing assembly Turns a page that is already printed on one side, so the other side can be printed. Laser printers Uses lasar beam to create an image. High cost of startup, prints come out dry Laser printer parts Imaging drum Coated with light sensitive insulating material Toner cartridge Primary consumable items in a laser printer Transfer roller Assists in transferring toner from the imaging drum to the paper Fuser assembly Made up of hot rollers, which melt the toner into the paper Pickup rollers Move the sheet of paper out the tray/cassette, then through the printer during the printing process. How laser printing works 1. Processing Data from source is converted into a printable form, printer does this from languages such as PS or PCL 2. Charging Image on the drum is removed and the drum is conditioned for the new image. 3. Exposing Photosensitive drum is scanned with laser beam, as the drum turns, an invisible image is created on the drum 4. Developing Toner is applied to a latent image on the drum. 5. Transferring Toner attached to the latent image is conducted to the paper. Corona wire places a positive charge on the paper. The image is now on the paper, and held in place by positive charge 6. Fusing Toner is permanently on the paper, printing paper is rolled between a heated roller and a pressure roller, the loose toner is melted and combined with the fibers in the paper. 7. Cleaning A printer can have a blade scraping the excess toner. Thermal printers and impact printers Thermal printers A roll of thermal paper is loaded, the feed assembly moves the paper through the printer, electrical current is sent to heating element in the print head to generate heat, the heated ares of the print head make the image on the paper. Last a long time cause of few moving parts. Impact printers Ribbon strikes paper, imprinting the character on the paper Uses continuous feed paper and can print carbon copies Perforated strips on the side are used to feed the paper and to preven skewing or shifting Virtual printers Print software either sends job to a file or transmits the info to a remote destination in the cloud for printing. Print to file Saved data in a file with the prn extension, which quickly can be printed at any time. Print to PDF Print to XPS Meant to be alternative to PDF. Introduced by microsoft Print to image To prevent others from copying the content in a document, choose to print an image file format. JPG or TIFF. Cloud printing Allows the user to connect the printer to the web. After it is connected, the user can send print jobs to the printer from anywhere that has internet access. 3D Printers Objects are first designed using a computer. 3D printers add the material used to create objects in layers or even small bits. Additive manufacturing machines. 3D printer parts Filament Material used to create objects. ABS, PLA, PVA, also from nylon, metal or wood. Feeder Takes filament from a feed tube that is placed into the extruder. The feeder pulls it down to be heated and exits through the hotend nozzle Hotend nozzle Filament is heated to the correct temperature, it is extruded from this nozzle. Axis One of several bars on which the hotend nozzle travels to dispense filament. Print bed This is a platform where heated filament will form the object. Installing a printer Before connecting a printer to computer, read installation instructions, since it may be that the printer driver needs to be installed first before the printer is connected. Remove anything that prevents moving parts from shifting during shipping. Connect corresponding cables. After cables are connected, attach power cable to the printer. Test printer functions Installation is not complete until all functions are tested. such as Print in draft mode Print double sided documents Print a collated document Use an optical character recognition application Collated printing Ideal when you need to print several copies of a multiple page document. Collate setting will print each set, some printers might even staple each printed set. Configuring options and default settings Configuring options Printer may have different configurations and default options. such as Paper type, print quality, color printing, black and white printing, grayscale printing, paper size, collate, print layout Media control options Common printer options, the following media control options are specific to paper Input paper tray selection Output path selection Media size and orientation Paper weight selection Printer output system Manages how the ink or toner goes on the media and include Color management and print speed Software optimization Print pool settings, color calibration and paper orientation Printers are calibrated using the printer driver software, makes sure the print heads are aligned and can print on different kinds of media. Hardware optimization Some printers can be upgraded to print faster and accommodate more print jobs by adding hardware. Firmware This procedure is similar to installing printer drivers. Printer memory All printers have RAM, upgrading printer memory increases printer speed and enhances complex print job performance Configuring printer sharing If you are unable to connect to a shared printer, it might not have the right drivers installed. Potential data privacy and security issues when sharing printers Hard drive caching Cached print files pose privacy and security risk because someone with access to the device could recover the files and gain access User authentication Permissions and authentication methods can be used to control access to the printer Data privacy Print jobs sent over a network could be intercepted and read, copied or modified Wireless printer connections Enables hosts to connect and print wirelessly using bt or a wifi connection. Print servers Purpose of print servers To enable network connectivity because these printers dont have built in network interfaces. Servers let multiple computer users acces a single printer, which has three functions Provide client access to print resources Administrate print jobs by storing them in a queue until the device is ready for them. provide feedback to users about the state of the printer Sharing printer has disadvantages, since it uses its own resources to manage print jobs coming to the printer. And the printer is not available if the user reboots or powers off the compute Software print servers The computer sharing the printer is running an OS that is not windows, then you can use print server software When downloaded and installed a special program it runs in the background and automatically detecting any compatible printers connected to the network. Hardware print servers Simple device with network card and memory, connects to network and communicates with the printer to enable print sharing It can manage network printing through either wired or wireless connections, one advantage is that server accepts incoming print jobs from devices, which frees the computers for other tasks. This is always available for users. Dedicated print servers For large networks with multiple LANs and many users, a dedicated print server is good. It is more powerful than a hardware print server and handles print jobs in most efficient manner. It requires the following to meet the requests of print clients Powerful processor Adequate storage space Adequate memory Module 2 Computer software, chapter 7, 9, 10, 11, 12 CHAPTER 7 Characteristics of laptops and mobile devices Mobility The ability to acces information electronically from different locations. Mobile connectivity us limited by availability of cellular or data networks. Laptops, tablets, smartphones, smartwatches Laptops Some peripheral connection options may require additional hardware, such as a dock or port replicator Smartphone characteristics Runs a special OS designed just for mobile devices. (Android and iOS). Compact and powerful. Uses cellular connectivity options for voice, text and data services Smartphone features Includes GPS that uses satellites to determine geographic location. C Can be configured to act as a modem that provides other devices to the cellular data network. Tablet Runs a mobile OS, have wifi and bt, some have cellular capability Smartwatch Wearable device, runs a special OS. Often includes body monitoring, can include GPS, wifi and limited cellular data connectivity Laptops components Motherboards CPU may be designed to use less power to ensure the system can operate for a longer period of time due to the battery source. Components designed for a laptop generally cannot be used in a desktop. Laptop display components LCD Uses fluorescent backlight to illuminate the display Digitizer Converts the touch actions into digitized signals Inverter Converts direct current into alternating current OLED Uses individually lit pixels CCFL Uses fluorescent tubes that are connected to an inverter used to convert AC to DC. Wifi antenna connectors Typically located above the sceen in laptops. Connected to a wireless card by an antenna wire and antenna leads Webcam and microphone Mostly built in today. Laptop configuration Power management ACPI creates a bridge between hardware and OS allowing technicians to create power management schemes to improve laptop performance. Managing ACPI settings in BIOS It has to be enabled in the BIOS/UEFI. Configuring power settings affect System states Battery and AC modes Thermal management CPU PCI bus power management Wake on LAN (WOL) (Might require a cable connection inside the computer from the network adapter to the motherboard. There are different levels of ACPI and eachc level means that the computer is consuming x amount of power. Wireless configuration Bluetooth Make sure tb is enabled in bios before installing and configuring a device Cellular WAN Laptops with cellular wan does nto require software installation. Tethering The ability for a cell phone to provide the ability to connect other devices. When a cellular phone allows wifi devices to connect and use the mobile data network this is called a hotspot. Laptop hardware and component installation and configuration Expansion cards Laptops compact design limit availability of some functions. Is solved by many laptops contain expresscard slots to add functionality. Expresscard/34 and expresscard/54. Flash memory External flash drive Removable storage device that connects to an expansion port (USB, eSATA firewire). External flash drives can be SSD or a smaller device. It provides fast access to data, high reliability and reduced power usage. Accessed by the OS in the same way that other types of drives are accessed Flash cards Data storage device that uses flash memory to store info. They are small, portable and require no power to maintain data. often used in laptops, mobile devices, and digital cameras. Flash card readers Secure digital (SD) and Secure digital high capacity (SDHC) Flash memory cards are hot swappable. Smart card reader Similar to a credit card, but with embedded microprocessor that can be loaded with data.. Used for telephone calling, payments. Microprocessor provides security, and holds more info than a magnetic stripe found on credit cards. SODIMM memory Mostly used in laptops. 72 pins and 100 pins config. Different laptops models require different types of SODIMMs Other mobile device hardware overview Wireless connections and shared internet connections Near field communication (NFC) Enables mobile devices to establish radio communications with other devices by placing them close together Infrared (IR) Can be used to control other IR controlled devices remotely, such as a TV Bluetooth Allows data exchange over a short distance between two bluetooth enabled devices. Network connectivity and email Wireless data networks Mobile devices typically have two wireless internet connectivity options Wi-fi Wireless network connection is provided using a local wifi settings Cellular Wireless connection is provided for a fee using cellular data, it requires cellular towers and satellites to create a mesh of global coverage. Cellular communication standards Industry standards have made interconnecftivity between cell providers simplified. They have also become less expensive and have not been adopted uniformly around the world. Airplane mode Turns off all cellular, wifi and bluetooth radio Hotspot When a cellular device is used to provide an internet connection to other devices. A hotspot referred to as tethering. Bluetooth pairing Consists of: Physical level Radio frequency standard Protocol level Devices connect to other bt enabled devices at this level. At this level, devices agree on when bits are sent, how they are sent and that what is received is the same as what was sent Matching email protocols Imap Allows user to organize email on the network email server, and download copies of the email. Enabling synchronization iOS devices support two types of synchronizing Backup Copies personal data from your phone to your computer or iCloud. Includes application settings, text messages, voicemails, and other data types. ‘ Sync Copies new apps, music, video, or books from itunes to your phone and from your phone to iTunes resulting in fyll sync on both devices. When connecting iOS device to iTunes, always perform a backup first. Backup storage location Backup straight from an iOS device Sync over Wi-Fi Chapter 9 Virtualization and cloud computing What is cloud Information is stored somewhere else, remotely accessible over the network and typically over the internet. It is like having a remote hard disk drive that you can access as any time anywhere. Cloud computing and virtualization Virtualization Enables a computer to host multiple independent virtual computers that share the host computer hardware. Virtualization software separates the actual physical hardware from the virtual machine instances, and VM have their own OS and connect to hardware resources through software runningon the host computer. Cloud computing Separates applications from the hardware, provides organization with on demand delivery of computing services over the network. Virtualization is the foundation supporting cloud computing, and it would not be possible without it. Traditional server deployment Organizations delivers applications and services to their user. And new servers are added if more users or new services are required Problems with traditional server deployment approach include: Wasted resources - Occurs when dedicated server sit idle for long periods waiting until they are need, meanwhile they waste energy Single point of failure - Occurs when a dedicated server fails or goes offline, no backup servers there to handle eventual failures. Server sprawl - Occurs when an organization does not have adequate space to house underutilized servers. Meaning servers take up more space than is warranted by the services that they provide. Virutalizing servers to use resources more efficiently addresses these problems Server virtualization Takes advantage of idle resources to reduce number of servers required to provide a service to a user Hypervisor A special program used to manage computer resources and various vm, it provides vm access to all of the hardware of the physical machine such as CPUs, memory, disk controllers and NIC. Each of these VM runs a complete and separate OS. Also known as virtual machine manager (VMM) Virtualization Enables the enterprises to consolidate the number of servers. Type 1 and type 2 hypervisors The hypervisor is the brain of virtualization, software used on the host computer to create and manage VMs. Allocates physical system resources, such as CPU, RAM, and storage to each VM needed Ensures the operation of one VM does not interfere with another Two types of hypervisor Type 1 Native hypervisor Bare metal hypervisor, typically used with server virtualization Runs directly on the hardware of a host, Manages allocation of system resources to virtual OS common in data centers and cloud computing Enables support for legacy software Type 2 Hosted hypervisor Hosted by an OS Commonly used with client side virtualization Virtualization software such as, virtual ´box and VMware workstation are type 2 hypervisor Works with host computer to create and use VM Client side virtualization Virtualization is used to optimize network resources and reduce equipment and maintenance costs, they also use client side virtualization which enable users with specific needs to run VMs on their local computer It is beneficial for IT people, since it provides users with resources to test new OS, software or to run older software. Can be used to sandbox and create a secure isolated environment Host computer Physical computer controlled by a user. VM use the system resources of the host machine to boot and run an OS Host operating system (Host OS) OS of the host computer, Guest OS OS that is running in the VM, independent from the host OS. Could be windows 10 and vm could be windows 7, or even windows and linux. Virtual machine requirements All VM share the following basic system requirements Processor support Intel VT AMD-V, the virtualization feature on these processors may need to be enabled. Multi Core processors are recommended as the additional cores increase speed and responsiveness when running VM Memory support Enough RAM needs to meet requirements of each VM and their guest OS Storage VM creates large file tostore OS, applications and all VM data, which requires large and fast drives Network requirements Not all VM require network VM uses virtual networka adapter to connect to the internet. All VM are as vulnerable to security threats as your physical computer, and they share resources, folder and files Cloud computing How we use the cloud Cloud based email cloud file storage solution Virtual desktop infrastructure Windows virtual desktop Cloud services Provide various services tailored to the user. but three main categories Software as a service SaaS Access to services, (email, calendar, communication and offline tools over internet) Accessed using a browser Used by end users Platform as a Service PaaS Access to OS, development tools. Useful to app and software developers Includes OS app stacks Infrastructure as a Service IaaS Provides organizations access to network equipment, virtualized network services, storage Used by organization infrastructure and network architects Public cloud Cloud based app and services are made available to the public Hybrid cloud Two or more clouds Each part remains a distinctive object, both are connected using single architecture Private cloud Cloud based apps and services offered are for specific organization such as the government Community cloud Exclusive for a specific community Software defined networking Approach centralizing and automates network control through software, enabling easier management, and flexibility. It separates control plane from data plane, allowing centralized management. Results in more adaptable secure and responsive network. Operating system features Multi user Two or more users have individual accounts that allow them to work with programs and peripheral devices at the same time Multitasking Computer is capable of operating multiple applications at the same time Multiprocessing The OS can support two or more CPUs Multithreading A program can be broken into smaller parts that are loaded as needed by the OS. Allows different parts of a program to be run at the same time. Operating system functions Control hardware access - Manage interaction between apps and hardware by using the device driver. When a new hardware device is installed the OS locates it and installs device driver for that component, if the device driver is not found, a technician must manually install the driver. Manage files and folders - OS creates file structure on HDD to store data, files and folders are organized for easy access and use. Folders can be stored in other folders called subfolders. Application management - OS locates an apps and loads it into the RAM of the computer. Provide a user interface and manage applications - OS enables user to interact with software and hardware by two types of user interfaces (CLI and GUI) 32 bit operating systems Have limited memory address space Have reduced performance with modern hardware 32-bit OS cannot be upgraded to 64-bit oS Can only address up to maximum of 4 GB RAM 64 bit operating systems Can run 32 bit applications through compatibility mode Includes enhanced security features May lack 64-bit drivers for very old hard drive Before installing new OS Storage media devices have to be chosen and prepared, for instance HDD, SSD or USB drives. Hard drives partitioning Hard drives are divided into areas called partitions, where each partition is a logical storage unit that can be formatted to store information such as data or applications. Two common scheme standards are Master boot record (MBR) - Contains info on how hard drive partitions are organized, Allows a user to choose from multiple OS, and commonly used in computer with BIOS based firmware 4 primary partitions, max size 2TB Partition and boot data stored in one place Compatible with all computers No partition table backup Globally unique identifier GUID partition table Designed as partition table scheme standard for hard drives, GPT makes use of a number of modern techniques to expand older MBR partitioning schemes. Often used in computers with UEFI firmware. Most modern OS now supports GPT 128 partitions, max size 9.4 ZB Stores partition table backup. Computer must be UEFI based and run 64 bit Primary partition Contains OS files and usually the first partition. Cannot be subdivided into smaller sections. GPT partitioned disk, all partitions are primary MBR partitioned disk, maximum of four primary partitions Active partition On MBR disks, active partition is used to store and boot OS Only primary partitions can be marked active on MBR disks. Only one primary partition per disk can be marked active at one time. Which usually is the C drive containing boot and system files. Are only found on drives with MBR partition tables Extended partition If more than 4 partitions are required on MBR partitioned disk, one primary can be designated an extended partition. Within this up 23 logical partitions/drives can be created. Common to use a primary partition for the OS and allow extended partition to occupy remaining free space on the hard drive. Logical drives cant be used to boot an OS, but good for storing user data. Only one extended partition per MBR hard drive, only found on drives with MBR partition tables. Logical drive Section of an extended partition, used to separate information for administrative purposes. Because GPT partitioned drives cannot have extended partitions they dont have logical drives either. Basic disk Default, and contains primary and extended partitions and logical drives formatted for data storage. Both MBR or GPT can be used as the underlying partition scheme of basic disks. Dynamic Disk Can create volumes spanning across more than one disk. Size of the partitions can be changed after they have been set, even if unallocated space is noncontiguous. Free space can be added from the same or different disk. Either MBR or GPT can be used as partition scheme of dynamic disks. Formatting This process creates a file system on a partition for files to be stored. File Systems File allocation table 32 bit (FAT32) Supports partition sizes up to 2TB used by windows XP and earlier OS versions. (Can contain OS files) New technology file system (NTFS) Support partition sizes up to 16 exabytes, in theory. Incorporates file system security features and extended attributes. exFAT (FAT64) Created to address some of the limits of FAT32 and NTFS when formatting USB flash drives, file size and directory size. One primary advantage is that it supports files larger than 4GB. Compact disc file system (CDFS) Created specifically for optical disk media Network file system (NFS) Network based file system, allowing file access over the network. From user POV there is no difference between accessing a file stored locally or on another computer on the network. NFS open standard, allowing anyone to implement it. Quick format Removes files from partition without scanning disk for bad sectors, which can prevent data loss in the future Full format Removes files from partition while scanning for bad sectors, required forall new hard drives, takes more time to complete. Windows boot sequence Power on self test (POST) MBR or GPT is read to find the boot loader NTLDR, BOOTMGR or GRUB loads the OS kernel Os kernel initializes system components and services User login/desktop screen is presented. Multiboot procedure Sometimes multiple OS can be installed in the computer, then you must install a boot manager which allows the user to choose which OS to use at boot time. It tracks specific partition where the OS was installed, the boot manager then direct the BIOS to the correct partition resulting in loading the desired OS Device manager Displays devices that is configured on a computer, and the OS flags devices that is not operating correctly Event viewer When system, user or software errors occur on a computer, the event viewer is updated with information about the errors, also records what type of problem, when it occurred, security and source of problem, the event ID number, and what user was logged in when the problem occurred. Display history of application, security and windows system that have been stored in log files Task manager Displays current applications and background processes that is running, here the user is able to close apps that is not responding. The user can also monitor CPU performance and virtual memory, view all active processes and info about network connections. Control panel Computer management console Allows managing many aspects of a computer and remote computers in one tool. Windows registry Database containing settings for windows and for applications using it Windows settings or control panel Management tool for windows and for applications using it. Authentication Enter a username and password to acces a user account Administrator account Can change settings globally and install programs Standard user account Run applications but they cannot install programs. Single sign on authentication Log in once to access all system resources. Recovery partition Contains image that can be used to restore the computer to its original configuration. Often hidden to preveent it from being used for another purpose. Option to restore from this is located in BIOS often Sysprep Program used to prepare the OS with different hardware configurations to install and configure the same OS on multiple computers. Ch 11 Windows configuration Windows versions Bitlocker Feature enables a user to encrypt all data on a disk drive or removable drive. Encrypted file system (EFS) Feature that allows user to configure file and folder level encryption Branch cache Allows remote computers to share access to a single cache of data from shared folders and files or document portals. Can reduce WAN traffic cause individual clients dont each need to download their own copy of cache data. The taskbar Provides access to important and commonly used features of windows, apps, files, tools, settings can be reached from this one place. Task manager Provides info about apps, processes and services running the computer, used to monitor system resources and programs that are using them, or terminate processed that are causing system issues Processes, performance, app history, startup, users, details, services. Windows file explorer Used to navigate file systems and manage the folder, subfolder and applications on storage media. Run as administrator User account control (UAC) is where admins can manage user accounts. Depending on file permission only users with correct access can open certain files. An admin password is required to use these features if the current user does not belong to the admin group Users folder Created for every account that has been configured on a pc System folder Contains necessary files for the operation of the windows Run as admin Allows files and apps that require higher user privileges to be opened A Archive file attribute Libraries Folders created for every user by default. Provides storage locations for common files and media.docx Microsoft word document This PC Provides access to various storage devices available on the computer Configure windows with control panels Windows 10, settings and control panels It offers two ways to configure the OS. Pc settings Provides more configuration options than control panel. Control panel More advanced alternative to the default settings app for configuration changes. And has several categories System and security Encryption settings, firewall settings, storage settings Network and internet Config, verification and ts of network and file sharing Hardware and sound Config of printers, media devices, power and mobility Programs Changes to installed programs and windows updates User accounts Enables administration of windows user accounts and UAC. Is created in UAC Admin accounts can change all system settings and access all files and folders on the computer. Standard user can manage most config settings that don't affect other users. Ease of access Provides options that makes windows easier to use, for stupid people. Clock and region Appearance and personalization Config of taskbar and navigation, file explorer, and available fonts. Credential manager Helps manage passwords, stored in secure location Sync center Allows files to be edited from multiple windows devices. Changes made on one device will be made on all devices that’s synchronized. Enables offline work and server copy is updated over the networ when device reconnects. Network settings Wireless wide are network, or cellular internet access technology. it requires an adapter to link to a cellular provider’s network through nearest base station or transmitter. Internal or external connected by USB, Bandwidth offered depends on technologies supported by adapter and transmitter (3g and 4g). Internet options General, security, privacy, content, connections, programs, advanced Network and sharing center Allows admin to configure and review almost all network settings on windows computer. From network status to changing properties of the protocols and services running on computer. Shows how the comptuere connects to a network. Homegroup Group of computers on the same network, simplifies sharing on simple networks. Requires little configuration. Display settings and control panel Display settings and configuration When using an LCD screen, set resolution to recommended settings (Native resolution) which sets video output to the same number of pixels that the monitor has. Display features Screen resolution Number of pixels displayed, expressed as a number of horizontal and vertical pixels Orientation Landscape horizontal or portrait vertical Refresh rate Amount of times a screen is redrawn per second Display colors Bit depth that display is configured to show Multiple displays Larger desktop can be configured by extending the display Power and system control panels Power options Allows you to change power consumption of certain devices or the entire computer. Maximize battery performance or conserve energy. Hardware and system settings together to manage power usage. Power options settings Require password on wakeup (7 and 8) Choose what power buttons do Choose what closing the lid does Create a power plan Choose when to turn off the display Change when the computer sleeps. Do nothing - COmputer continues to run at full power Sleep - Documents applications and state of the OS are saved in RAM, allows computer to power on fast, but uses power to retain the information in RAM Hibernate - Documents, apps and the state of the OS are saved on a temporary file on the hard drive. Computer takes little bit longer to power on than the sleep state. Dont use power to retain any info on the hard drive Turn off the display - Computer operates at full power, display is turned off. System control panel item Allows users to view basic system info, access tools and configure advanced system settings. Increasing performance To enhance OS performance, change virtual memory settings. When RAM is insufficient it creates a paging file on the hard drive that contains some of the data from RAM, when data is required back into the RAM it is read from the paging file, it is much slower than accessing ram directly. Hardware and sound control panels Device manager Lists all devices installed, making it easier to diagnose and resolve device problems. Update a driver - Change currently installed driver Roll back a driver - Change currently installed driver to the previously installed driver Uninstall a driver - Remove a driver Disable a device Devices and printers View of devices connected to a computer, typically external devices. Allows you to quickly add a new device to the computer. Devices typically shown in devices and printers include Portable devices Devices plugged in via USB Printers connected to your computer or available on the network Compatible network devices connected to your computer, such as network enabled scanners, or network attached storage devices (NAS) System administration Administrative tools Collection of tools used to monitor and configure windows operation. Collection of shortcuts taht open i file explorer. Computer management An administrative tool to manage aspects of your computer and remote ones in just one tool. Provides access to three groups of utilities Event viewer Allows viewing the history of application, security and windows system events, these are stored in log files. Valuable tool when ts. Each logged event is identified by its type or level Info Warning Error Critical Success audit Failure audit Local users and groups Efficient way of managing users, create new and assign to memberships in groups. Groups have rights and permissions assigned and suitable for each individual user. Windows provides default user accounts and groups to make managing users easier Administrator Full control of computer and access to all folders Guests can access the computer through a temporary profile that is created at logon and deleted on logoff. Disabled by default Users Can perform common tasks, running apps and accessing local or network printers. A profile is created and persists on the system. Performance monitor Customized performance graphs and reports to be created from a wide range of hardware and software components. System configuration Msconfig a tool to identify problems keeping windows from starting correctly. Use disk management to do the following Mount disk Intialize disk Extend partition Split partition Shrink partition Disk management utility Allows you to view drive status, assign or change drive letters, add drives and arrays, designate the active partition Drive status Foreign Dynamic disk that has been moved to a computer from another windows computers Healthy Initializing Disk that is being converted into a dynamic disk Missing Dynamisk disk that is corrupted, turned off or disconnected Not initialized Disk that doesn’t contain a valid signature Online Dynamic/Basic disk that is accessbile Online (Errors) As above but with I/O errors detected on dynamic disk Offline Dynamic disk that is corrupted or unavailable Unreadable Mounting a drive Making a disk image file readable as a drive. (ISO File). Adding arrays Can create mirrored, spanned or raid 5 arrays from multiple dynamic disks. Disk optimization Used to maintain and optimize disk storage. Files increase in size data becomes fragmented and spread over nonadjacent clusters on the hard drive resulting in longer time to locate and retrieve each section of the data. To solve this Disk defragmenter gathers the noncontiguous data into one place making the OS run faster Dont disk defragment on ssd since they are optimized by the controller and firmware the use. System requirements Verify system requirements are met when purchasing or installing an application. such as Processor speed 32 or 64 bit x86 or other RAM OS and version Hard disk space available Peripheral devices Command line tools Powershell Offers more advanced features than cmd prompt. More powerful as well. Command shell. More straightforward and easy to use for simple tasks Windows networking Domain and workgroups Methods for organizing and managing computes on a network. Domain Group of computers and electronic devices with common set of rules and procedures. LDAP is a protocol allowing computers to access data directories that are distributed throughout the network Workgroup Collection of workstations and servers on a LAN designed to communicate with one another. Each individual workstations controls its user accounts, security information and access to data and resources. All computers on a network must be part of either a domain or a workgroup. Network file sharing and mappings networks Secure and easy way to provide easy access to network resources. Mapped drive Useful way to access a single file, specific folders or an entire drive between different OS over a network Printer sharing A printer can be attached to a computer via USB or direct network connection (local printer). This can be shared on the network, it is attached to a pc which works as the print server. Setting a network profile Public network disables file and printer sharing and network discovery on the link and PC is hidden from other devices Private networks allows user to customize the sharing options. Profile is for use on trusted networks. The PC is discoverable by other devices. Ch 12 Mobile, linux, and OSX operating systems Mobile Operating systems Open source vs Closed source Source code Sequence of instruction written in human language, before it's turned into binary. Important component of software, it allows users to analyze and modify the code. Open source When developer provide the source code Closed source When developer does not publish the source code Applications and content sources Apps are written and compiled for a specific mobile OS. Automobile apps Apps in vehicles. used through carplay. Screen orientation Used in portrait or landscape mode Sensor known as an accelerometer detects how the phone is being held and adjusts accordingly. Screen calibration LCD screen for mobile devices uses most battery power, adjust brightness to conserve battery power. WiFi Calling Instead of cellular carrier’s network, it’s possible to make a call using local hotspots. Good in areas with poor cellular coverage, since the wifi hotspot fills the gaps. NFC payment Premium SMS based transactional payments Consumers send SMS to a carrier’s phone containing a payment request. Charge is added to phone bill. Direct Mobile Billing Allows charge to be added to mobile service bill. Secure and convenient, no need for bank cards or credit cards Identifies through two fauctor authentication Mobile Web Payments Contactless Web or dedicated apps to complete transaction. Relies on Wireless application protocol and credit card or similar Contactless NFC Near field communication, mobile payment used in physical store transactions. Digital wallet. Virtual private network Private network using a public internet to connect to remote sites/users together. Allows data encryption, communication between client and server is secure Virtual assistants Program that understands natural conversational language and perform tasks for end user. Siri. Google now Rely on AI, machine learning and voice recognition to understand voice commands. Methods for securing mobile devices Passcode, swipe, pattern, fingerprint, face lock Restrictions on failed login attempts After entering the wrong password the device will lock itself. Possible to set a device to perform defined actions after incorrect attempts Cloud enabled services for mobile devices Remote backup Mobile device data can be lost if device fails or loss/theft of device. Backup to ensure it can be recovered. Remote backup is when the device copies its data to cloud storage using a backup app. User can enable automatic backups to the cloud for data, apps and settings. Also use third party apps for backups, such as dropbox. Store mobile device data in the cloud iTunes, store iOS backups on local PC Remote lock and remote wipe Prevent data on a lost device from being compromised Remote lock Allows a user to lock device with a passcode so other cannot gain access to the data Remote wipe Deletes all data from the device and returns it to a factory state. Software security Antivirus Smartphones and other mobile devices are computers and also vulnerable to malware Antivirus apps are available, and depending on permissions granted some file scanning can occur automatically while some has to be initiated manually. iOS does not allow automatic or scheduled scans Mobile device apps run in a Sandbox Sandbox It is a location of the OS keeping code isolated from other resources and other code Making it hard for malware to infect a mobile device since apps are run inside the sandbox. Malicious apps has access to any resources that were allowed permission during installation Trusted app source Authenticated and authorized by a service provider Service provider issues the developer a certificate to use to sign their apps and identify them as trusted. Malware rarely damage mobile devices More likely that a mobile device transfer malware to another device, such as laptop/desktop. Malware may be downloaded from email, internet or another device, it could be placed on a laptop next time it is connected to the mobile device. Prevent malware from infecting additional device Use a firewall. Firewall apps for mobile devices can monitor app activity and prevent connection to specific ports or IP addresses. Mobile device firewall usually work at a higher permission level since they control other apps. Rooting and jailbreaking Mobile OS are protected by software restrictions. Rooting and jailbreaking are methods for removing restrictions and protections added to mobile OS Allows user to gain full access to file system and super user admin permissions Exploits vulnerabilities in the OS, when a “hole” is found, a program is written which becomes the jailbreak software Patching and updating OS Updates on OS add functionality or increase performance Patches can fix security problems and/or issues with hardware and software. Two types of baseband updates PRL and PRI. PRL Configuration info that cellular phone needs to communicate on networks other than its own, so a call can be made outside of the carrier’s network. PRI Configures data rates between a device and a cell tower, Ensuring the device is able to communicate with the tower at the correct rate Linux and macOS operating systems Linux OS Two files system, 64 bit file system. Support fat and fat32 NFS can be used to mount remote storage devices into local file system Allows support creation of swap partition, which is used by the OS to supplement system RAM. MacOS Have their own file system Their file system supports many of the same features as NTFS in windows., but not native file/folder encryption Linux backup and recovery Linux No built in backup tool exists. Uses commercial and open source solutions. They offer, local/remote/cloud backup locations, data encryption compression, periodic scheduled backups. Restores from any particular backup. Can be customized by ther user installing and removing software components MacOS backup and recovery MacOS Backup tool called time machine Users pick an external drive to be used as a backup destination device and connect it to the MAC. TM prepare the disk to receive backups, and when ready it perform backups periodically Local snapshot A type of backup that is stored on your mac if time machine backup disk is not available Overview of disk utilities Used to diagnose and solve disk related problems. Disks Utility used in Linux User can perform common disk related tasks including partition management, mount or unmount, format disk Utility disk Used in macOS Used to backup disks to image files and perform an image recovery to disk from image files Supports main disk maintenance as well as verify disk permissions and repair disk permissions. Repair disk permission Common TS step in macOS Maintenance tasks available using disk utility software Partition management - Partitions may need to be created, deleted or resized Mount or unmount disk partitions - Relates to process of binding a partition of a disk or a disk image file to a folder location Disk format - Before a partition can be used, it must be formatted Bad sector check - Flagged disk sector is harmless to the OS, since it no longer stores data. Many bad sectors is a sign of a failing disk Query S.M.A.R.T. attributes - Detects and reports attributes about a disk’s health. Its purpose is to anticipate disk failure which allows users to move data to a healthy disk before disk becomes inaccessible. Linux and MacOS best practices Scheduled tasks Computer need periodic preventive maintenance to ensure best performance. They should be scheduled and performed frequently to prevent/detect problems early Backups and disk checks should be scheduled and performed automatically Backups and disk checks Time consuming tasks. So scheduled tasks allows computer to perform them when system is not used. CLI utility “CRON” is responsible for scheduled tasks. OS updates When vulnerability is found, it can be used for creation for malware or virus. Updating the OS/firmware and antivirus and antimalware are methods used to prevent malware from attacking computers. Firmware updates Held in non volatile memoru, ROM or Flash. Type of softwware designed to provide low level functionality for a device. Antivirus and antimalware Relies on code signatures to operate Signature files contains a sample of code used by viruses and malware, based on these the programs scan contents of a computer disk comparing the contents of the files with samples stored in a signature file If a match is found, the programs alerts the user of possible malware. Signatures Contains sample of code used by viruses and malware (antivirus/antimalware) Keychain Security credentials manager for macOS Patches OS updates released periodically by OS vendors to address new know vulnerabilities Gnome keying Security credentials manager for Linuz Cron Service used to schedule tasks on Linux and macOS Module 3 Computer Network and security, chapter 5, 6, 13 KLART NETWORK COMPONENTS AND TYPES Host device Also known as end devices, they are on the end of the network. And host devices since they typically host network applications, such as web browsers and email clients that use the network to provide services to the user. Intermediary devices Computer networks contain many devices that exist in between the host devices, they make sure that data flows from one host device to another host device, the most common are the following Switch Connects multiple devices to the network Router Forwards traffic between networks Wireless router Connects multiple wireless devices to the network and may include a switch to connect wired hosts Access points Connects to a wireless router and is used to extend the reach of a wireless network Modem Connects a home or small office to the internet. Network media Communication across a network is carried on a medium, the medium provides the channel over which the message travels from source to destination. For instance LAN and WAN Mobile hotspot A cell phone configured to allow other devices to connect via wifi Tethering Process of connecting another device to a cell phone so that the connected device can access the internet Cable Uses coaxial cables to deliver variety of content including tv channels, internet and voice calls Broadband Technology that uses different frequencies to send multiple signals over the same medium Cellular Uses towers distributed throughout user’s coverage area to provide seamless access to phone and internet services Fiber For internet connections to homes and business that uses light to transfer data Satellite For rural markets that do not have a DSL or cable provider DSL Digital phone service that can also connect to the internet. Personal area network (PAN) Network that connects devices such as mice, keyboards, printers, smartphones, and tablets within the range of an individual person. Often connected with bluetooth technology Local area network (LAN) Network that connect devices using wire cables in a small geographical area. Typically owned by an individual, such as in home or small business. Virtual LAN (VLAN) Allows admin to segment ports on a single switch as if it were multiple switches, this provides more efficient forwarding of data by isolating traffic to only those ports where it is required, also allow end devices to be grouped together for admin purposes Wireless LAN (WLAN) Similar to LAN, but wirelessly connects users and devices in a small geographical area instead of using a wired connection. It uses radio waves to transmit data between wireless devices. Wireless mesh network (WMN) Uses multiple access points to extend the WLAN, two wireless AP extend the reach of the WLAN within the home. Effective way to use WMN to quickly add new areas of coverage of your network Metropolitan area network (MAN) Network that spans across a large campus or a city, it consists of various building connected through wireless or fiber optic media. Wide area network (WAN) Connects multiple networks that are in geographically separated locations. Your service provider for your home or mobile device connects you to the largest WAN, the internet. Virtual private network (VPN) Used to securely connect to another network over an insecure network, such as the internet. NETWORK PROTOCOLS, STANDARDS AND SERVICES TCP/IP Model (Transmission control protocol / Internet protocol Consists of layers performing functions necessary to prepare data for transmission over a network. Transmission control protocol TCP Responsible for tracking all network connections between a user’s device and multiple destinations. A reliable full featured transport layer protocol ensuring that all of the data arrives at the destination. Provides reliability and data acknowledgement The transport is analogous to sending packages that are tracked from source to destination. There are three basic operations of reliability Numbering and tracking data segments transmitted to a specific device from a specific application Acknowledging received data Retransmitting any unacknowledged data after a certain period of time User datagram protocol UDP Together with TCP they operate at the transport layer. Similar to placing a regular non registered letter in the mail. The sender of the letter is not aware of the availability of the receiver to receive the letter. Post office is not responsible for tracking the letter or informing the sender if the letter does not arrive. UDP also provides basic functions for delivering data segments between appropriate applications, with minimal overhead and data checking. UDP is known as a best effort delivery protocol. And this is unreliable because there is no acknowledgement that the data is received at the destination Fast and delivers data as it arrives Internet protocol IP Responsible for adding addressing so that data can be routed to the intended destination Wireless protocols Wlan protocols The institute of electrical and electroning engineers’ IEEE standards specify the radio frequency, speeds, and other capabilities for WLANs. Different standards offers different range, speed and frequency Bluetooth, NFC, RFID Wireless protocols for close proximity connectivity includes Bluetooth, Radio frequency identification RFID and Near field communication NFC Bluetooth A bt device can connect up to seven other bt devices, it operates in the 2.4 to 2.485 ghx radio frequency and is typically used for PANs. Bluetooth incorporates AFH which allows signals to hop around using different frequencies within the 2.4 - 2.485 range which reduces the risk of interference when multiple bt devices are present. Wireless PAN technology that supports up to seven connected devices. Radio frequency identification Uses a much bigger range to uniqely identify items. Active RFID tags contain a battery able to broadcast their ID up to 100 meters Passive RFID tags rely on the RFID reader to use radio waves to activate and read the tag, typically used for close scanning, range up to 25 meters. Near field communication Designed to be a secure method to complete transactions. Based on a unique ID a payment is charged directly. A secure close proximity transaction system, typically used for wireless payments Zigbee and Z-wave Smart home standards, allowing users to connect to multiple devices in a WMN, and often managed from a smartphone app Zigbee Uses low power digital radios. used by low cost and low speed devices. Smart home standard. Z-wave Wireless communication protocol, operates on low energy radio frequency, ideal for devices requiring minimal power consumption Can support up to 232 connected devices in the same WMN LTE Technology meets standards for fourth generation mobile phones 802.11ac standard all wlans shall be using when newly implemented. Client and server roles All computers connected to a network that participate directly in network communication are classified as a host (end device). They perform a certain role, some perform security tasks while others provide web services. A host that provide a service is called a server, and a host that use these services are called a client Each service requires separate server software. For instance a server requires web server software in order to provide web services to the network. A computer with server software is capable of providing services simultaneously to several clients. A single computer can also act as several servers, (File, web and email server File client and server File server stores corporate and user files in a central location Client devices acces these files with client software such as windows explorer Web client and server Web server runs web server software and clients use their browser software. Firefox, chrome, to access web pages on the server DHCP Server Dynamic host configuration protocol A host needs IP address information before it can send any data on the network. Two important IP address services are DHCP and DNS DHCP is used by ISP, network admins, and wireless routers to automatically assign ip addressing information to hosts. DHCP operation Works in a client/server mode, DHCP clients request available IP configurations from a DHCP server. DHCP server is configured with a scope of addresses that it can lease to requesting DHCP clients. DHCP reservations Some hosts such as servers and printers can always be assigned the same IP address when they connect. A DHCP server is configured with a reserved list of ip addresses based on the requesting dhcp clients mac address. DNS server, Domain name system Method used by computers to translate a domain names into IP addresses. For instance it is much easier for me to remember google.com rather than its IP address, and this is thanks to DNS DNS Records When a client does not know the IP address of a web domain or email domain name, it sends a DNS query to the DNS server identified in its internet protocol (IP) configuration What is the IPv4 address for the google.com domain name DNS server keeps a list of domain names and ip addresses information in RR which is stored on a dns server in a dns zone database. Spam management DNS service is abused by threat actors to assist in their SPAM campaigns. Uses Sender policy framework, domainkeys identified mail, domainbased message authentication reporting and conformance programs to avoid all this spam shit Print server Enables multiple computer users to access a single printer. Three functions Provide client access to print resources Administer print jobs by storing them in a queue until the printer is ready and then feed or spooling the print info to the printer Provide feedback to users. File server FTP File transfer protocol, provides ability to transfer files between a client and a server. Requires two connections between the client and the server, one for commands and replies and the other for the actual transfer of the file. But it comes with many weaknesses, therefore a more secure file transfer service shall be used, such as: FTP Secure FTP client request the file transfer to be encrypted, the file server can accept or deny the request. SSH FTP (SFTP) Used to establish a secure file transfer session Secure copy (SCP) Web server Web resources are provided by a web server. The host accesses the web resources using the HTTP ro the secure version HTTPS. These are a set of rules for exchanging text, graphic images, sound, and video. HTTPS adds encryption and authentication services using secure sockets layer SSL protocol, or Transport layer security TLS. Proxy server Authority to act as another computer, often used to act as storage cache for web pages that are frequently accessed by devices on the internal network. Can hide the IP addresses of internal hosts since all requests going out to the internet are sourced from the proxy server’s ip address. Syslog server Allows networking devices to send their system messages across the network to syslog servers. It provides three primary functions Can gather logging information for monitoring and TS Can select type of logging information that is captured Can specify destinations of captured syslog messages. Network devices Network interface card (NIC) Provides the physical connection to the network at the PC or other end device. Ethernet NIC are used to connect to ethernet networks, and wireless NICs are used to connect to wireless networks. Most NICs in desktop computers are integrated into the motherboard or connected to an expansion slots. NIC also come in USB form factor. Repeater Regenerates weak signals. Extend the distance a signal can travel. Today, mostly used to regenerate signals in fiber optic cables. Hub Receive data on one port and then send it out to all other ports. It extends the reach of a network by regenerating the electrical signal. Can also connect to another networking device, such as switch or router. Legacy devices and shall not be used in today’s networks. Bridge To divide LANs into segments. They keep a record of all devices on each segment. It can filter network traffic between lan segments, which reduces the amount of traffic between devices. Switches Replaced hubs and bridges. It microsegments a LAN, meaning it segments network traffic and switches filter by only sending data to the device it is being sent. This results in higher dedicated bandwidth to each device on the network. Microsegmetns a lan and forwards data based on the MAC address. Switch operation Every device on a network has a MAC address which is unique. This is hardcoded by the manufacturer of the NIC. When a device sends data, switches enter the device’s MAC address into a switching table that records MAC address for each device connected to the switch and records which switch port can be used to reach a device with a given MAC address. Wireless Access points (AP) Provide networka access to wireless devices. It uses radio waves to communicate with wireless NIC in devices and other Wireless AP. It has limited range Router Switches and Wireless AP both forward data within a network segment. Routers can have the functionality of a switch or a Wireless AP. However routers connect networks and switches use MAC addresses to forward traffic within a single network. Routers use IP addresses to forward traffic to other networks. In bigger networks, routers connect to switched, which then connect to LAN, the router serves as the gateway to outside network. Integrated router Includes a switch and a Wireless AP. In some cases it is better to buy just one device rather than buying and administrating several devices. Firewalls Integrated router typically contains a switch, router and a firewall. Firewalls protect data and equipment on a network from unauthorized access, and it resides between two or more networks. Does not impact the PC performance. IDS and IPS IDS Passively monitor traffic on the network.Have disappeared in favor of IPS, but the detection feature of and IDS is still part of any IPS implementation. IDS copies the traffic stream and analyzes it rather than the actual forwarded packets. It then compares this with known malicious signatures. IPS Based on IDS technology, however, all inbound and outbound traffic must flow through it for processing. Does not allow packets to enter target system without being analyzed first. Biggest difference between IDS and IPS is that IPS responds immediately and no malicious traffic may pass. Unified threat management Includes functionality of and IDS/IPS, as well as stateful firewall services, which provides stateful packet filtering by using connection information. It also tracks each connection by logging the source and destination addresses along with source and destination port numbers. Called next generation firewall, (hardware firewall) Power over Ethernet PoE Method for powering devices that do not have a battery or access to a power outlet. They transfer small amounts of DC current over an ethernet cable along with data to power PoE devices. Can receive power over an ethernet connection at distances up to 100 m away Ethernet over Power (Powerline networking) Uses existing electrical wiring to connect devices. “No new wires” ability to connect a device to the network wherever there is an electrical outlet. Sends information by sending data on certain frequencies. Cable types Coaxial and twisted pair cables use electrical signals over copper to transmit data. Fiber optic cables use light signals to transmit data. These cables differ in bandwidth, size and cost. Coaxial cables Copper or aluminum. Carries data in form of electrical signals. Can carry more data since it is shielded unlike unshielded twisted pair UTP. But UTP is cheaper and easier to install and TS Twisted pair cables Copper cabling, used for telephone communications and most ethernet networks. Twisted to prevent crosstalk. Consists of four paris of color coded wires. Twisted pair wire schemes Two different schemes. And they are paired according to color Fiber optic cables Composed of two kinds of glass and a protective outer shield. Since it uses light to transmit signals it is not affected by EMI or RFI unlike the twisted pair cables. All signals are converted to light pulses as they enter the cable and converted back to electrical signals when they leave it. Is durable and used in harsh environmental conditions. Can go farther and greater bandwidth than cable made of copper or other metals. Multimode fiber Uses LED emitters and popular for LANs. WDM Technology used to send and receive on a single strand of fiber Single mode fiber Uses laser and popular for long distance runs. Core Element in a fiber optic cable through which light pulses travel Cladding ACts like a mirror reflecting light to keep it traveling down the fiber. Applied networking Fingerprint address Usually does not change and is used to uniquely identify you, no matter your location. It cooperates with the NIC. (Mac address/Physical address) it is 48 bits. is hardcoded onto the ethernet or NIC card by the manufacturer The mailing address Can change, it is your location (IP Address). Assigned by network admins based on the location within the network. Mac addresses do not change when the device is moved compared to the IP address do change. IPv4 Legacy protocol, 32 bit addresses, 4.3 billion unique addresses. IPv6 128 bit addresses, 340 undecillion unique addresses, basically an unlimited supply., ensuring plenty of room for expansion. Unlike the iPv4 this has enough addresses to give each device a unique IP, eliminating the need for NAT and simplifying network architecture. Unlike the ipv4 Static addressing In small network, you are able to configure each device with proper IP addressing, a unique IP address is given. This is known as static IP addressing IP address - Identifies this device on the network Subnet mask - Is used to identify the network on which this device is connected Default gateway - Identifies the router that this device uses to access the internet or another network Optional values - Such as preferred DNS server address and the alternate DNS server address Dynamic addressing Instead of manually configuring all devices, you can implement DHCP server, which automatically assigns IP addresses, which simplifies the addressing process. DHCP can assign following configuration info to a host: IPv4 address Subnet mask Default gateway Optional values, such as DNS server address. DNS records When a client doesn’t know the IP address of a web domain or email domain name it sends a DNS query to the DNS server identified in its IP configuration. To answer the DNS keeps a list of domain names and IP addresses info in RR, which is a list stored on a DNS server in a DNS zone database. VLAN Provide segmentation and organizational flexibility in a switched network, groups of devices within a VLAN communicate as if each device was attached to the same switch. Based on logical and not physical connections. Ping Is used to test connections between computers. , it sends an ICMP echo request to the IP address you entered. It is also possible to test connectivity to a website by entering the website’s domain name. Quality of service QoS Gives you the option to guarantee that certain traffic types are prioritized over traffic that is not as time sensitive Universal plug and play UPnP Protocol enabling devices to add themselves to a network without the need for user config. Easy, but it is not secure, it is also easy for malware to use UpnP protocol to redirect traffic to different IP addresses outside your network, potentially sending sensitive information to a hacker. DMZ - Demilitarized zone Network that provides services to an untrusted network. Email, web or FTP server is often placed into the dmz so traffic using the server does not come inside the local network. But these servers in the dmz are not protected in the same way as the interal network from attacks. Wireless router allows you to create a dmz for one device by forwarding all traffic ports form the internet to a specific IP or MAc address. Security threats Malware Most common threat for computers and data contained on them is malware, which is software developed by cybercriminals to perform malicious acts. (malicious software) Typically installed on a computer without the user knowing it. Once a host is infected it, the malware could Change computer configuration Delete files or corrupt hard drives Collect infromation stored on the computer without the user’s consent Open extra windows on the computer or redirect the browser. Cybercriminals use variety of methods to infect hosts including the following  User visiting infected website User has outdated antivirus software Downloading a “free” program Open unsolicited email Insert USB stick you find in public area Non compliant and legacy systems are especially vulnerable to software exploitations. A non-compliant system is one which has not been updated with OS or application patches or missing antivirus and firewall security software. Viruses and trojan horses Most common type of computer malware is a virus, they require human action to propagate and infect other computers. A virus is able to infect a computer when a victim opens an email attachment, opens a file on a USB drive, or downloads a file. It hides by attaching itself to computer code, software or documents on the computer. Viruses can Alter, corrupt, delete files, or erase entire computer drives. Cause computer booting issues Capture and send sensitive information to attackers Access and use email accounts to spread. Types of viruses Attacks boot sector,, file partition table, or file system Boot sector virus Attacks boot sector, file partition table, or file system Firmware virus Attacks device firmware Macro virus Uses the MS Office macro feature maliciously Program virus Virus inserts itself in another executable program Script virus Attacks the OS interpreter which is used to execute scripts Types of trojan horses A program that looks useful but also carries malicious code. Often provided with free online programs such as computer games, unsuspecting, users download and install the game, and also installing trojan malware Remote access Trojan enables unauthorized remote access Data sending Trojan provides the attacker with sensitive data, such as passwords Destructive Trojan corrupts or deltes files Proxy Use the victim’s computer as the source device to launch attacks and perform other illegal activites Security software disabler Trojan stops antivirus or firewalls from working Keylogger Trojan actively attempts to steal confidential information, such as credit card numbers, by recording key strokes entered into a web form. Other types of malware Adware Distributed by downloading online software, Pop up windows may be difficult to control as new windows can pop up faster than the user can close them Ransomware Denies user access to their files by encrypting them and displaying a message demanding a ransom for the decryption key. Rootkit To gain administrator account level access to a computer. Difficult to delete because they can alter firewall, antivirus protection, system files and even OS commands to conceal their presence. Spyware Similar to adware, but used to gather information about the user and send to criminals, can be low threat, gathering browsing data, or it can be a high threat capturing personal and financial information. Worm Self replicating program that propagates automatically without user actions by exploiting vulnerabilities in legitimate software, it uses the network to search for other victims with the same vulnerability. The intent is to slow or disrupt network operations. Anti malware programs Seven step best practice procedure for malware removal 1. Identify and research malware symptoms 2. Quarantine the infected systems 3. Disable system restore (windows) 4. Remediate infected systems 5. Scheduel scans and run updates 6. Enable system restore and create restore points (windows) 7. Educate the end user Anti malware program are started when a computer boots checking the system resources, drives and memory for malware, it then runs continuously in the background Most common method of malware delivery is through email, or through applications that are installed. Especially from software installed from untrusted sources Windows uses the system administrator and standard user accounts along with user account control (UAC) to help prevent installation of untrusted software. Signature file updates Always download signature files from the manufcturer’s website to make sure the update is authentic and not corrupted by any malware. This can create a huge demand on their website which they solve by creating multiple download sites called mirrors, but before entering them make sure that the link is from the manufacturer’s website. Remediating infected systems When malware protection program detects that the PC is infected it removes/quaranties the threat, but the PC is most likely still at risk. When malware is discovered, you should udate anti malware software and perform full scans of all your media. If Malware is found on a business computer it shall be removed from the network to prevent other computers from becoming infected as well. Unplug all network cables and disable all wireless connections. Network attacks Perform an information query of a target Initiate a ping sweep of the target network Initiate a port scan of active IP addresses Run vulnerability scanners Run exploitation tools Types of TCP/IP attacks Denial of service DoS Attacker completely overwhelms a target device with false requests co create a denial of service for legitimate users, may be caused for malicious reasons or used in conjunction with another attack. A single machine/user sends a massive amount of traffic/requests to a target system, in hope to crash its system Distributed Dos Using many infected hosts “zombies” to overwhelm a target. A stronger Dos Attack with more devices and bots. Attackers control zombies using a handler computer and botnet is an army of compromised hosts DNS poisoning Attacker successfully infects a host to accept a false DNS records pointing to malicious servers. Traffic is diverted to these malicious servers to capture confidential information Man in the middle Attacker intercepts communication between two hosts, if successful the attacker could capture packets and view their content, manipulate packets and more. Replay Attacker captures authenticated packet, altere