Section 1: All about the CompTIA+

What is the CompTIA A+?

Computing Technology Industry Association been around since the 1980s. Intel, Microsoft, Cisco all the big-tech players are a part of CompTIA. Aside from big tech memberships there are individual memberships such as the A+, Network + etc. A+ Certifications are Designed to test an IT Technician with 6-9 months of experience.

Why get A+ Certified?

• Default entry level cert.
• Gives a feel of your skills.
• Many companies require A+ Certifications.
• Money.
• Won’t get you in the door, will help!

What is on the CompTIA A+ Core 1 (220-1001)?

Go to CompTIA.org

Exam Domain 1.0 Mobile Devices – 14%

Laptop hardware components
Mobile device types (tables, smart phones, VR headsets, etc)
Set up mobile devices (syncing and networking)

Exam Domain 2.0 Networking – 20%

Networking hardware devices (routers, switches, firewalls, etc)
Configure a basic SOHO network (wireless access points, IP addressing, IoT devices, etc)
Networking configuration concepts (IPv4 vs. IPv6, DNS, VPNs, etc)
Internet connections and network types (cable, DSL, Fiber, LANs, etc)

Exam Domain 3.0 Hardware – 27%

Cables and connectors (USB, Ethernet, HDMI, Lightning, Thunderbolt, etc)
Motherboards, CPUs, power supplies, RAM, hard drives and SSDs
Peripherals (printers, monitors, keyboards, microphones, etc)
Given a scenario, exploit local host vulnerabilities
Summarize physical security attacks related to facilities
Given a scenario, perform post-exploitation techniques

Exam Domain 4.0 Virtualization and Cloud Computing – 12%

Cloud computing (IaaS, SaaS, PaaS, elasticity, on-demand cloud services, cloud file storage, etc)
Client-side virtualization (virtual machines, emulators, hypervisors)

Exam Domain 5.0 Hardware and Network Troubleshooting – 27%

Resolve problems with best practices and industry standards
Troubleshoot RAM, motherboards, CPUs, power supplies, hard drives, display issues
Troubleshoot mobile device issues, printers, wired/wireless networks

Section 2: Safety and Professionalism

Tools of the Trade

• Mobile/PC Repair Kit
• Multiple Thumb drives
• Voltage Tester/Volt-ohm tester

Troubleshooting Theory

Always consider corporate policies, procedures, impacts before implementing changes.

1. Identify the problem – talking to the user. Ask questions, when was the last time it worked? Review the logs if necessary.
2. Establish a Theory – what is the probable cause? Question the obvious. Check network cards.
3. Test the Theory – check to determine the cause. If your wrong, try something else. Escalate the Issue – if necessary, call someone who knows more than you. Call tier 2 or 3 or whoever you can ask for an opinion.
4. Establish a Plan of action – to resolve the problem or implement a solution.
5. Verify full system functionality – if possible, implement preventative measures
6.  Documentation– document the findings and the outcome of the situation which can influence company policies in the future.

Section 3: The Visible Computer

Primary PC Connections

• The System Unit contains the motherboard, CPU, RAM and hard drives; every other device is a peripheral
• Monitors provide visual output and web cameras provide visual input
• Keyboards, mice and game controllers provide input
• Printers create paper output
• Speakers and headsets make audio output
External Connections

Might need to photoshop together some notes for this part…

Bios Reset Button
USB Connectors (A-C, Thunderbolt, etc.)
Network Cable Connections (RJ-45)
Sound Jacks (round, fiber optic)
DVI (Digital Visual Interface)
Display Port (Chamfer on one side)
Mini-Display Port (for laptops)
HDMI (High-Definition Multimedia Interface)
Power Connection
I/O Buttons/switches

Older Connectors (Might be discontinued)

Mini -DIN (PS/2) – Purple, Green, Old school keyboard and mouse connectors, old
Parallel Port (LPT Port) – Magenta, Used exclusively for printers, old
Serial Port – Like and inside out VGA
VGA (Video Graphics array) – for monitors
S-Video Connectors

Inside the PC

Chipset – Contains instruction pertaining to the limitations, functionality and compatibility of the motherboard and attached hardware.

Also briefly covered;
Ram Sticks, SSD, CPU, Cooling, and Expansion slots.

What is a computer?

A computer gets work or play done. A computer will have a CPU, RAM, mass storage and an operating system Laptops, mobile devices, and Internet of things (IoT) devices are all computers.

Section 4: CPUs

What is a CPU?

Central Processing Unit runs programs. Every CPU has internal features to process commands. Every CPU runs code based on a specific machine language. CPUs use pipelines to optimize the processing of commands.
• The Data Bus is used to transport data around the motherboard, to, and from the CPU
• CPU’s receive instructions in Binary, it has an internal code book that identifies the instruction pattern
• Microarchitecture is the underlying circuitry at the core of the CPU.

CPU Speeds and Cores

• 1 Hertz = 1 “times” per second • 1 GHz = 1 billion “times” per second
In Computer speak “times” means Computations per second or Clock Speed (when referencing speed, we mean top speed).
The 2 main manufacturers or Intel and AMD.
Motherboards max out at 400mhz these days. CPUs can go up to 4ghz.
Clock Multiplying is how the motherboard accommodates to the speed of the CPU.
Overclocking makes your motherboard unstable in the long term.
CPUs usually have multiple cores nowadays.

Caching

Hard drives are Fast, RAM is faster, CPU is fastest, the bus is typically pretty slow in comparison. These extreme differences in speed are what create the need for Cache. Cache is built into the CPU as a result of the speed differential between accessing data from the RAM and simply performing the calculation in the CPU. Cache is RAM, but in the CPU, we call it SRAM. It Stupid expensive so we use it sparingly.

It’s common to have thee caches in a CPU L1(the fastest), L2 and L3(the slowest).

CPU Sockets

Microarchitectures change from model to model which creates changes in the CPU sockets. CPU sockets are the mount where a CPU connects to the motherboard. CPU Socket can help todefine the shape, the size, the pins and overall, from factor of the CPU as well as its microarchitecture.

Installing a CPU

• Make sure you have the right socket and speed for your motherboard
• Always use thermal paste between the CPU and the fan
• Connect the fan to a power source

Liquid Cooling
• Third part fans are often more efficient than OEM fans
• Liquid cooling uses a pump, a radiator, and a cooling block with liquid to remove heat
• Liquid cooling reduces fan noise

Section 5: RAM

RAM Technology

Dual channel memory provides simultaneous access to two RAM modules when reading or writing.
Synchronous RAM is technology that keeps RAM timing matched to system clock.
Single and double-sided RAM modules are configurations that determine the capacity of RAM modules.

SDRAM – Older RAM Technology, Synchronous DRAM 168 pins
DDRRAM – Double Data Rate RAM, twice as fast as SDRAM, For every two ticks of the system clock 2 units of data are delivered 184 pins
DDR2 RAM – Successor to DDR, twice as fast as DDR, has 240 pins
DDR3 RAM – Successor to DDR2, twice as fast as DDR2, has 240 pins
DDR4 RAM – Successor to DDR3, twice as fast as DDR3, has 288 pins

RAM Capacity

• RAM has a speed specification and a capacity specification
• RAM capacity thresholds double due to square-like microarchitecture
• RAM comes single and double-sided versions
• Motherboards offer multi-channel and single channel memory
• RAM Should be identical in each channel but not the same across all channels.

RAM Features

• Parity vs ECC – Typically in servers, has an extra chip that checks for RAM errors, can function with a failed memory chip, ECC is only for motherboards that support it.
• SO-DIMM – Small Outline Direct Inline Memory Module, smaller, usually for laptops 200 – 260+
• SPD Chip – Serial Presence Detect Chip, allows system to query the ram chip and detect specifications, manufacturer, capacity etc.  Tool to use: CPU-Z

Installing RAM

• Check Motherboard Manual to ensure that you’re installing the right capacity and speed RAM stick.
• Line up the notch and drop the RAM straight into the slot
• Watch when the system boots to verify the system “sees” the installed RAM
• Make sure RAM is fully installed and channels are properly filled

Section 6: Firmware

What is BIOS?

• BIOS is programming that enables interaction with the motherboard before the OS loads
• BIOS is stored in nonvolatile media, thus called Firmware
• POST routines are built into firmware
• The system setup utility is also part of the firmware
Services – Bios programs that make hardware functional
Drivers – make hardware functional in the operating system.

POST (Power On Self-Test)

• POST runs at boot, requesting devices to check themselves.
• POST errors manifest as specific beep codes or display (text) codes.
• POST cards enable testing of “dead” computers.

System Setup

• UEFI replaces traditional 16-bit BIOS in modern systems
• The system setup enables custom information about changeable devices
• System set-up enables changes to CPU frequencies, RAM timings, BIOS passwords, boot options, & more

Troubleshooting Firmware

CMOS – Complimentary Metal-Oxide Semiconductor, powers the system clock which also keeps track of time. Time is usually kept up-to-date with a battery, the CMOS battery is typically a CR2032

• The Real-time clock battery keeps system time without external power.
• System Setup allows for changes; exit without saving is an option.
• Reset System set-up for defaults.
• Flash the ROM chip to update firmware.

Section 7: Motherboards

Form Factors

• Form Factors refer to the sizes of motherboards which are standardized across the industry based on  the I/O Area (where all the ports are located)
• There are Four Main Form Factors: • ATX • MICRO ATX • ITX (very-rare) • Mini-ITX

Chipsets

• In the beginning All Chips were specialized. One chip to interface with the hard drive, another chip to interface with the mouse etc. Eventually, chips became less specialized these became known as Chipsets.
• The earliest chipsets were divided into North Bridge and South Bridge, both of which were essential for different reasons.
Northbridge – Faster, interface to CPU, Memory controller, Expansion Buses
Southbridge – Slower, USB Port, Hard Drives and Keyboards etc.
• Todays Chipsets are even less specialized; The CPU handles North Bridge, and the South Bridge is on the motherboard itself
Chipset – are the most important aspect of the motherboard to know about, they define RAM capacity, USB capabilities and much more. It’s called a Chipset because they combine functions from many single function chips.

Touring the Motherboard

• SATA (Serial Advanced Technology Attachment) Cables – Used to connect hard drives to the system.
• Capacitors – Capacitors regulate the voltage from the power supply to the rest of the motherboard. Capacitors. Work. Hard. When capacitors fail, they tend to ‘bubble or dome up’.
• Expansion Slots – used to expand the I/O Capabilities of the motherboard
• PCIe (Peripheral Component Interconnect Express) – the dominant Expansions slot, works in serial or parallel depending on the use case.
• Parallel vs Serial – Sending data in parallel on multiple wires versus sending all the data on one wire.

Touring the case

• Cases offer standardized standouts for mounting various motherboard form factors
• Better cases offer cable management features
• Pick a case that has support for a number of drives of different types as needed.

Installing a Motherboard

• Install RAM, CPU, CPU-Fans and Video Cards unto the Motherboard first.
• Plug your board into a power supply FIRST to insure it boots
• Mount your I/O shield first, make sure your I/O shield is oriented properly.
• Start dropping it into the case, just line up the standouts

Section 8: Power Supplies

The Power Supply

• Power Supplies don’t really supply power. Technically they are Step down Transformers that convert AC power into DC power.

• Standard connectors for motherboard are 20-24 pin ATX and 4-8 pin P4
• ATX Power Connector – 3 main types of power cables 12v(yellow) 5v(red) 3.3v(orange)
• ATX12 Connector – Newer power cable standard
• Molex – Old power cable
• Mini-connector- Floppy driver power connector, has chamfers that prevents improper insertion
• SATA power connection – Hard Drive, Optical Media Power Cable
• PCIe Connector – Video Card power connector

Mounting a Power Supply

• Remember heat flows out the back
• The Cables usually have Chamfers or Clips that show insertion orientation
• Usually the power supply gets mounted to a bracket and inserted into the chassis and held in place by that same bracket

Choosing a Power Supply

• Volts X Amps = Watts
• Resistance in the circuit can increase or decrease based on the Circumstances. Power gets lost in the form of heat etc.
• 80 Plus certifications are a good way of knowing the efficiency of the power supply. They start at 80 (Bronze) and move up to 92% (Titanium)
• Always get a Power supply that supplies more Wattage than you need
• Modular power supplies allow you to plug in cables as needed which makes cable management nicer

Cooling your PC

Electronics Typically Generate Heat especially computers.
Heat Sink – Pulls heat from the CPU and blows it out the back
Power supplies pull air from the bottom and shoot air out the back
PWM Connectors – 4-pin connectors used for Fans
Cool Tool: Speed Fan

Troubleshooting Power Supplies

Power Supplies are the most likely component to go bad.
They’re either going to Die really fast, or really slow
Look for Burning smell or smoke [fast death]

Look for unexpected shutdowns, No-boots but boots when power switch is left off for a while [slow death]

Use a power Supply Check tool. Check the Voltage
Use a voltmeter to check the cable Voltage.

Troubleshooting Core Components

• Incorrectly installed CPUs or RAM can make it seem like your PC is dead (fans running, no boot).
• Install core components and test before mounting into the case
• Errors in System setup can cause a dead PC; try clearing the CMOS jumper
• Windows offers memory diagnostic tools to help with potentially bad RAM

Section 9:  Mass Storage Technologies

Introduction to Mass Storage

• There are many types of mass storage used today, including hard disk drives, solid state drives and optical media.
• Regardless of the media your operating system sees mass, storage as a string of Logical Block Addresses
• There is a difference between decimal values and IEC values

Magnetic Disk Drives

• Magnetic disk drives use spinning platters to store data via magnetism and read/write heads
• Hard disk drives come in 3.5”, 2.5” and 1.8” physical sizes
• We use the Advanced Technology Attachment(ATA) protocol to communicate with hard disk drives
• The dominant ATA is called Serial ATA(SATA)

Solid State Drives

• Most popular, Faster, More expensive
• Solid state drives (SSDs) store data using chips; there are no moving parts
• Data is stored in blocks and pages
• SSDs come in traditional 3.5” and 2.5” sizes, but also come in M.2 format
• Some SSDs use the very fast NVMe protocol instead of SATA for increased performance
• NVMe (Non-Volatile Memory Express), Faster than SATA (looks like laptop memory)

SCSI (Small Computer System Interface)

• The Small computer Systems Interface (SCSI) pronounced scuzzy, is an ancient standard that still has great support
• The old parallel SCSi is long gone, but the SCSI language
• Lives on in serial SCSI versions
• Two modern SCSI standards are SAS (Serial Attached SCSI) and ISCSI
• iSCSI uses SCSI commands sent over Ethernet

Boot Order

• When a system Boots, it looks for a bootable device
• it’s important to make sure the system looks for the correct boot devices
• The boot order is defined in the CMOS system setup or UEFI

Section 10:  Implementing Mass Storage

New Installation – First Drive

• The first drive on a system relies on the OS install program to provide partition and format functions
• The partitioning and formatting tools in installation programs provide a subset of tools when compared with their main tools
• Installation tools may provide features not normally seen anywhere else (such as swap file creation)

• A swap file is a system file that creates temporary storage on a solid state drive or hard disk when the system runs low on memory. The file swaps a section of RAM storage from an idle program and frees up memory for other programs,

RAID (Redundant Array of Inexpensive Disks)

• RAID 0 – Striping, requires a minimum of 2 drives, Fastest but less safe because it stores files fragmented form across multiple hard drives, For Large documents.
• RAID 1 – Mirroring, uses 2 or 4 Drives, Stores files twice across all drives, slower but safer due to redundancy.
•RAID 5 – Striping with Parity – Uses a minimum of 3 drives, Files are saved in pieces with redundancy, parity is used to re-assemble/re-create files in the event a single drive is lost.
• RAID 6 – Requires a minimum of 2 drives
• RAID 10 – Requires a minimum of 4 drives
• RAID 0+1 – Mirroring & Striping

Dedicated RAID Expansion Card

Hardware RAID

• Hardware RAID requires a controller to configure the RAID arrays
• Hardware RAID has its own BIOS that comes with a special system setup to configure the RAID array
• The completed array looks like a single drive to the operating system

Mass Storage Troubleshooting

• RAID NOT FOUND/RAID NOT WORKING – Re-seat, check power, re install
• READ/WRITE FAILURE – Old HDD problem, use S.M.A.R.T. , replace the drive
• LOUD CLICKING – TERMINAL HDD, NEEDS TO BE REPLACED
• FAILURE TO BOOT – Check boot order
• DRIVE      NOT RECOGNIZED – Failing drive, needs to be initialized
• OS NOT FOUND– Check boot order, check flash drives
• CONTINUOUS REBOOTS – OS Corruption, re-install OS

Section 11:  Essential Peripherals

Optical Media

• Compact Disc (CDs) store 650-700mb of data (74 minutes).
• CDFS (CD File System), CD-ROM, CD-R, CD-RW
• Digital Video Disc(DVD) – store from 4.37 GB to 15.9GB. Can be DUAL LAYER OR DOUBLE-SIDED
• Blu Ray Discs (BDs) store 25GB to 50GB
• All optical media comes in Read-only memory(ROM), Write-once(R) and Write-many (RW/RE) versions. Optical Media Devices are all SATA Connectors these days

USB Standards (Universal Serial Bus)

The de-Facto standard for plugging in a peripheral device.
USB Standards are defined by there max speed.
USB Standard 1.1 – had 2 speeds 1.5mbps/12Mbps(megabits per second) (WHITE)
USB 2.0 – 480 Mbps (BLACK)
USB 3.0 (5Gbps) Gigabits per second (BLUE)
USB 3.1 Gen 1 (5 Gbps)
USB 3.1 Gen 2 (10 Gbps)
USB PORTS ARE COLOR CODED!!!

Understanding USB

• All USB devices connect to USB controllers built into the motherboard of the system; the USB controller is in charge of all connected  USB devices
• This creates an upstream/downstream concept
• The USB type-A connectors plug into downstream USB ports; USB type-B connectors Plug into upstream USB ports on peripherals

Configuring USB

• First Install the Driver, then plug it in (usually)
• Windows 10 Usually does that for you.
• Operating Systems have 1000s of built-in drivers which usually work
• USB Lock – Cyber Security tool often used in Law enforcement
• USB Ports can be disabled

Thunder and Lightening

• Thunderbolt – is a general purpose I/O port that runs at
10 Gbps(Thunderbolt 1), 20Gbps (Thunderbolt 2) 40 Gpbs(Thunderbolt 3)
• Thunderbolt typically uses a mini-DisplayPort or a USB C connector
• The Lightening standard is exclusive to Apple products
• Lightening uses a proprietary Lightening connector

Keyboard and Mice

• Keyboards use either a USB or PS/2 Connection (Purple)
• Mice either a USB or PS/2 Connection (Green)
• Game Controllers often have proprietary connection that requires a converter
• Keyboard, video, mouse (KVM) switches enable multiple computers to share a single keyboard, monitor and mouse

Sight and Sound

• Sound is commonly built into today’s systems
• Speaker systems include satellites and subwoofers, called 2.1 or 5.1 systems
• Sound uses 3.5mm jacks or SPDIF
• Many devices, like webcams or headsets include speakers

Readers and Scanners

• Smart Cards have RFID chips that store credentials (like credit cards)
• Smart card/magnetic readers are used to read cards, used for authentication, on laptops
• Flash memory readers read many types of flash memory
• SD cards are very popular flash memory
• Scanners read paper documents. Automatic document feeders enable scanning multiple pages
• Barcode and QR code scanners read printed coded labels

Using Expansion Cards

• Always handle expansion cards carefully, avoiding the contacts
• Apply power, data connections or dongles as needed
• Make sure to add the correct driver, check device manager to confirm good drivers
• A new installation is a common place for Blue screen of death screens

Section 12:  Building a PC

The Right PC for the Job

Thick Client – Basic Office Computer
Thin Client – rarely stores it own data, relies on connectivity, Basic applications
Design Workstation – Powerful Multi-core processor and High end Video Cards and High RAM
Virtualization Workstation – Maximum RAM and CPU Cores
NAS – is a Box that sits on your network that Shares Files. Data Reliability is important for NAS so they will typically be using a RAID array.
Gaming PC – Multi-core Processor, High-end Graphics Card, Maximum RAM, SSDs
Video Editing – High RAM, High Storage, High-End Video Cards 

Section 13:  Display Technologies

Monitor Technologies

• A monitor is composed of individual picture elements (pixels); the total pixels across and down is the resolution
• Liquid Crystal Display (LCD) monitors use liquid crystals to allow light to pass or not pass for each color in a pixel
• LCD backlights are fluorescent or LED lights and shine through the liquid Crystals
• Organic LED (OLED) doesn’t use a backlight, as the pixels make their own light
• Digital Light Processing (DLP) uses a grid of tiny mirrors that shine through a color wheel to create an image.

LCD Breakdown

• An LCD panel is made from a set number of Pixels (Picture Elements) which filters light based on the electrical current running through them. The distribution of lights is what creates the pictures
• The back panel (backlight unit) distributes the light emanating from the CCFL(Cold Cathode Fluorescent Lamp) or LED backlights
• Inverters convert DC power back into AC power for fluorescent lights LEDs don’t need inverters

Graphics Cards and Connections

• Nvidia, AMD (ATI) and Intel make the majority of GPUs
• All graphics cards have RAM to help resolve the screen
• Many CPUs come with built-in GPUs (CPU + GPU = APU)
• VGA uses an analog signal; DVI uses a digital or analog signal(DVI-D(Digital) vs DVI-I(Analog and Digital))
• DVI Supports DRM (Digital Rights Management)

Installing a Graphics Card

• Almost all graphics cards use 16-lane PCIe slots and one or two PCIe power connectors
• With multiple graphics cards, define the primary card in system set-up
• Some systems provide riser cards for extra graphics cards
• Always run the system at your monitors native resolution

Projectors

• Projectors have resolutions and aspect ratios just like monitors
• Projectors usually have either DLP or LCD technology. DLP (Digital Light Processing) uses tiny, moving Mirrors to create the projected image.
• Lumens Define the brightness of the Projector
• Make sure you understand throw, pincushion, keystone and skew

Troubleshooting Monitors

Overheat Shutdown – Bad Fan, needs more ventilation/Cooling
Dead Pixels – Pixels that don’t Fluctuate, Can’t be fixed
Artifacts – Pictures that were there but aren’t anymore, check Video RAM, no replacement so replace video card
Incorrect color patterns – check your cables, Video RAM, change the card itself
DIM Image – Change the CCFL, try turning the brightness back up
Flickering Image – Re-seat cables
Distorted Image – Make sure you are running at the native resolution
Burn In – Doesn’t happen anymore, on plasma monitors
Oversized Image Icons – Adjust in windows settings

Section 14:  Essentials of Networking

Introduction to Networking

• LAN computers connect with Ethernet
• Ethernet frames are standardized as 1500 bytes
• A MAC (Media Access Control) address is a made up of 12 Hexadecimal (48 bits) characters, it uniquely identifies a host on a LAN. MAC addresses are also called Physical adress
• Use Ipconfig (Windows) or Ifconfig (Linux) to view MAC
• Anatomy of a Data frame (Google IT Support Certificate)

Hubs VS Switches

• Hubs are old Technology; They make a copy of all the data received and forwards it to all nodes on the network
• Switches filter traffic based on the MAC Address by watching the data-frames
• Switches provide better bandwidth than HUBs because of the difference in how data frames are handled

Hexadecimal

• Hexadecimal (base 16) enables discussion of long strings of 1s and 0s
• Each hex character represents 4 binary numbers (0000-1111)
• In hex, numbering goes 0-9, a-f for 0-15

WANs and Routers

• Every computer has a MAC Address and an IP address
• Switches connect (up to 1024) computers in a LAN
• Routers connect multiple LANs together in a WAN
• Routers use logical addressing (IP addressing) to identify WANs and to determine local versus -non-local traffic

Cables and Connectors

• Coaxial cables us RG ratings and F-type connectors
• Most Networks use twisted pair cabling
• Fiber optic cables use light, rather than electrical pulses
• Twisted pair cabling have different category (Cat) ratings

Cat Ratings
Cat 5 – 100mbps  
Cat5e – 1gbps
Cat6 – 1 Gbps up to 100m 10 gbps up to 55m
Cat 6a – 10gbps at 100m segments

• Solid-core cable is used in walls and horizontal runs because it is good for long runs and is not exposed to frequent bending. It is not used in environments where frequent bending occurs such as in patch panels, workspaces, or anywhere that it will be fixed regularly be people handling, stepping on or tripping over it.
• Plenum describes any type of cable with a fire-resistant jacket NOT a networking cable.
PVC – Cheap, burnable

Crimping Cables

• Use crimping tool to remove jacketing and reveal the twisted pairs• Use a crimping tool to attach UTP cable to crimp (like RJ-45)
• Two standards: T568A and T568B
• Straight-through cable has same standard on each end
• Crossover cable has different standards on each end which allows for two computers to speak to each other depending on the network card

Structured Cabling

• Main Distribution Frame Typically is where your equipment rack is stored. It protects the switches and your Data
• Horizontal runs from wall outlet to patch panel through walls/ ceilings cannot be more than 90m
• Use Punchdown tool to connect cable to patch panel
• Use tone generator/tone probe to locate cables
• Use TDR for testing runs

Section 15:  Local Area Network

Introduction to TCP/IP

• ARPANET formed (basis for internet)
• TCP/IP adopted as protocol for ARPANET/the Internet
• IP addresses have four octets between 0-255
• Classful address scheme for locations and sublocations

Network IDs and Subnet Masks

• Every Machine that connects to the internet must have and I{ address, Subnet Mask and Default Gateway
• Network and Sharing Center, where you go to troubleshoot network and connectivity.
• Manual Settings = Static IP address

Special IP addresses

• (over?) 4 Billion IPv4 Addresses
• Class A address has only the first octet defined 1.0.0.0 – 126.0.0
• Class B addresses have the first 2 octets defined 128.x.0.0 – 191.x.0.0
• Class C addresses have the first 3 octets defined 192.x.x.0 – 223.x.x.0
• Private versus Public
• Loopback addresses for self-reference (localhost) 127.x.x.x

NAT (Network Address Translation)

• Network address Translation (NAT) saves IP addresses (we are running out)
• With NAT, internal networks use private IP addresses and share a public address
• All gateway routers are NAT-enabled by default
• Networks that use NAT are invisible to the public internet

Dynamic IP Addressing

• Dynamic Host Configuration Protocol (DHCP) automatically assigns IP information to hosts
• Gateway routers commonly are DHCP servers for their internal LANs
• If a DHCP client can’t find the DHCP server, it will use an APIPA(Automatic Private IP Address will default to a class B) address 169.254.x.x
• Use the ipconfig/renew command to force a new connection to the DHCP server
• Use the ipconfig/release command to disconnect from DHCP server
• Built-in troubleshooter does this

IPv6

• IPv6 addresses use 128-bit addressing scheme
• IPv6 addresses use a hexadecimal notation
• Link-local addresses are used for local connections
• Global unicast addresses are used to connect to the internet

Port Numbers

• Port numbers get data to the correct application
• There is always a source and destination port number
• Resource Monitor shows the connections on a System
• Memorize all port numbers listed on the CompTIA A+ 1001 objectives
21 – FTP
22 – SSH
23 – Telnet
25 – SMTP
53 – DNS
80 – HTTP
110 – POP3
161/162 – SNMP
143 – IMAP
443 – HTTPS
3389 – RDP
137-139 – NETBIOS/NETBT
445 – SMB/CIFS
427 – SLP
548 – AFP
67/68 – DHCP
389 – LDAP

TCP UDP and ICMP

• Transmission Control Protocol (TCP) is connection-oriented and sends multiple packets
• User Datagram Protocol (UDP) is connectionless, but also sends multiple packets
• Internet Control Message Protocol (ICMP) is connectionless and always sends a single packet
• Protocols are differentiated from one another based on the anatomy of the datagram or the Protocol Data Units (PDU)

Understanding DNS

• Domain Name system (DNS)  resolves fully-qualified domain names (FQDN) to IP addresses
• FQDN have up to 255 characters, including dots.
• In the past every computer had a host file, the host file was used to by the computer to resolve what web addresses go to which domain
• DNS replaced host files
• DNS root servers control one FQDN ‘.’
• First level domains = .com .edu .gov
• Second level domains = totalsem.com, google.com
• Authoritative(Root, First-level & second-level) and Recursive server(the DNS server that interacts with the authoritative server on behalf of the client)
• Referred to as a hierarchical structure

Working with DNS

• DNS is provided by your DHCP server
• Use ipconfig/all to see a system’s DNS servers
• You can statistically configure DNS and still use DHCP for IP addressing
• Have an alternative public DNS server in case your DNS server is down
• Use nslookup to verify a DNS server is running

Windows Naming

• Microsoft invented Netbios, a naming system that pre-dates DNS, that name is setup during the OS setup.
• Windows naming is designed for LANs
• When you install windows, you give the computer a windows name
• All Windows systems will be a member of a domain or a workgroup
• Workgroups vs Domains, a workgroup is for home use, a domain is typically for business use and requires specialized equipment and software (Active Directory Domains)
• Homegroups are a more secure automated organization, but still a workgroup

Routers

• Routers filter and forward traffic based on IP addresses
• A routing table determines where to filter or forward ip packets
• Every routing table has a default gateway that sends all data unless otherwise specified
• A SOHO(Small Office/Home Office) router is usually a router and a switch and access point
• Some Routers use web connections, some use console ports

Basic Router Configuration

• Configure both the WAN(ISP) and LAN(Local) connections on your router
• Avoid default settings for basic configurations (IP, SSD Name, SSD Password, etc)
• Don’t create too large of a DHCP pool
• DHCP reservations set aside IP addresses in the DHCP pool

Advanced Router Configuration

• Quality of service (QoS) a toolset that allows us to control the amount of bandwidth a device gets based on IP address, MAC address or other criteria
• Link Layer Discovery Protocol (LLDP) and Universal Plug and Play (uPNP)
• Simple Network Management Protocol enables querying of network devices used by network Administrators to know what routers are out there, how much bandwith it being used and when.

VLANS

• VLANS enable network segmentation without adding hardware
• Internet Explorer/ Edge may work better
• Configure VLAN-capable switches via IP address and web browser
• Use firmware interface for managing VLANs
• Firmware interface also enables features such as port security

Network Troubleshooting (Wired)

• Connectivity problems caused by physical or software faults
• Check IP addressing possible IP conflicts (Modern OS usually catch this)
• Limited connectivity look for APIPA addresses 169.254.x.x. DHCP server problems
• Network ID problems can indicate rogue DHCP (in cases where you know your network ID)
• External interference can create network problems
• Slow transfer speeds, check your network task manager. Check who or what is using the net. (use QoS)

Section 16:  Wireless Networking

Wireless Network Hardware

• IEEE 802.11 Standard (20 Year old Standard)
• Wireless clients connect to Wireless Access Points
• A wireless access point (WAP) is a bridge between an Ethernet Network and a Wireless (802.11) Network.
• 802.11 works in one of two modes: infrastructure mode(WAP) or ad hoc mode(Wired?)
• Omnidirectional Antenna
• Dipole Antennas create a flat signal that arcs out on the x axis in all directions
• Patch antennas propagate outward in one direction
• Yagi Antennas (Highly Directional Antenna) Propagate out like an American football
• Parabolic Antenna (Directional)
• Use the right antenna for the Job

Wi-Fi Standards

• IEEE 802.11 Standard uses the 2.4 and 5-GHz ISM (Industrial Scientific and Medical) Radio Bands
• A Band is a range of Radio Frequencies
• 2.4Ghz (802.11) uses14 premade channels  2.412GHz – 2.484GHz
• 5Ghz (802.11) uses many premade channels with some channels not in use  5.150GHz – 5.875GHz
• Band usage and relative speeds of the different 802.11 extensions
802.11a ran at 54 Megabits per Second on the 5Ghz Band
802.11b ran at 11 Megabits per Second on the 2.4Ghz Band
802.11g ran at 54 Megabits per Second on the 2.4Ghz Band
 (Backwards compatible to b but not a)
802.11n ran at 100 Megabits per Second on the 2.4/5Ghz Band
(ran on both bands! Unilateral backwards compatibility, introduced MIMO (Multiple in/Multiple Out))
802.11ac ran at x Megabits per Second on the 2.4/5Ghz Band
(Current standard, Improves MIMO to Multi User MIMO)

Basic WAP Set-up

• A site survey shows available channels in an ISM band (Ubiquities WiFiMan)
• You must create a Service Set Identifier (SSID)
• Most WAPs support multiple SSIDs
• You can define extensions to support, channels, and channel width

Connecting to a Wi-Fi network

• All wireless clients can scan the 802.11 spectrum, finding available SSIDs
• You must know the SSID and password to connect
• Clients create profiles that store the SSIDs and their passwords

It’s a Huge Mesh

• Mesh Networks are often a great wireless solution for SOHO environments.
• Mesh networks have a base station and beacon devices that connect to the base station to extend range
• Mesh networks use their own encryption
• Mesh networks are universally easy to configure

Beyond Wi-Fi

• RFID (Radio Frequency Identification) uses tiny radios activated by the energy of the scanning device
• Think of RFID as tiny chips or stickers that are powered up by  radio waves emitted from a device intended to read RFID information (NFC)
• NFC(Near Field Communication) requires extremely close proximity
• Bluetooth is like 802.11 but pairs with devices to function as point-to-point

Troubleshooting Wireless Connections

• Wi-Fi analyzers always help. For Example, WiFiman
• No connectivity- maybe your trying to get to an SSID that doesn’t exit (technically) Check if they changed the WAP name or password.
• Low Radio frequency signal, you may be too far away, or bad antenna orientation
• Slow Transfer Speeds – interference from the environment. New Walls? Baby monitors? Try the wifi Analyzers
• Intermittent Connectivity – Low signal, interference, Too many people on the wireless network

Section 17:  The Internet

Beyond LAN

Local Area Network (LAN) – Computers share the same Network ID
Wide Area Network (WAN) – two or more LANs interconnected by one or more routers
Metropolitan Area Network (MAN) – A bigger WAN or multiple WANS
Personal Area Network (LAN) – is a point-to-point connection used only in Bluetooth connections

Internet Tiers

• The Internet is composed of many organizations that connect to to each other
Tier 1 are providers that do not pay anyone (peering)
Tier 2 are providers that pay some Tier 1s but also peer with Tier 1 and Tier 2w
Tier 3 providers pay Tier 1 or Tier 2 providers

Dial-up Connections

• Dial-up also goes by the name plain old telephone service (POTS)
• Dial-up plugs RJ-11 connectors to the phone system
• Modems convert analog POTS to digital COM port connections
• Modems connect to other modems using a phone number

Broadband Connections

• Broadband is a high speed, always on connection
• Digital Subscriber Line (DSL) runs on top of telephone service
• Data Over Cable Service Interface Specification (DOCSIS) uses cable connections
• Satellites are handy for more remote locations
• Many metro areas provide native ethernet for an ISP

Firewall and Servers

• All internet connections require a client and a server
• One of the Primary functions of firewalls is to block ports
• Client and server networks firewalls
• Firewalls block ports on an incoming vs outgoing concept
• Server must not block incoming ports on the ports to which they listen (Port 80)

FTP

• File Transfer Protocol (FTP) is used to transfer files from one system to another
• You need an FTP client to utilize the protocol; Every web browser is an FTP client
• FTP uses port 21 (Passive Mode)
• FTP in active mode is the traditional method, 5x faster. Sends return traffic on port 20
• Active mode FTP requires the router to use port triggering to allow port 20 incoming

E-mail

• michaelm@totalsem.com
• E-mail uses Simple Mail transfer Protocol (SMTP) to send e-mail from a client to an e-mail server.
• Use Post Office Protocol v3 (POP3) or Internet Message Access Protocol (IMAP) to pull e-mail down from e-mail server.
• SMTP uses TCP port 25; POP3 uses TCP port 110; IMPA uses port 143
• Be aware of secure port numbers
• Setting up an e-mail account requires knowledge of theIP addresses or DNS name for the different servers

Proxy Servers

• A proxy server acts as a go-between (a proxy) between a client and a server
• Proxy servers are application-specific (e.g. a Web Proxy for HTTP and HTTPS)
• A proxy server provides firewalling, check for malware, ban bad URLs
• Applications must know the address of the proxy server

Virtual Private Networks (VPNs)

• Virtual Private networks (VPNs) use internet to create a private connection to a remote network
• We need a VPN client program that connects to a VPN server at the remote network
• The VPN client needs to know the IP address of the VPN server to make the connection

Internet of Things (IoT)

Section 18: Virtualization

Understanding Virtualization

• Virtual machines are self-contained computers running within a host OS
• Most be compatible with the CPU AND enabled in the BIOS/UEFI
• Hypervisors support multiple VMs
• A type 1 hypervisor runs directly on top of the hardware as an OS
• A type 2 hypervisor runs as an app in an OS

Your First Virtual Machine

• Setting up a new VM takes a few steps
• Install a hypervisor like, Oracle VirtualBox
• Create a Virtual Machine in the Hypervisor
• Download OS .iso file and point to its file location on your hard drive to begin the set-up process

Advanced Virtualization Set-up

• You can modify Virtual Hardware easily, such as add a “drive”
• Bridge a VM to connect same network (and DHCP server) as host OS
• Use NAT to put a VM in a unique network ID
• Use NAT network to put multiple VMs into a single network ID

Cloud Computing

• Cloud computing moves the VMs “out there”, but accessible via IP
• Cloud computing enables rapid elasticity, on-demand scaling, and resource pooling
• IaaS moves network tasks such as firewalls into the cloud ()
• PaaS moves the machine into the cloud so you can concentrate on apps ()
• SaaS moves apps to the Cloud, such as Google Docs ()

Cloud Ownership

• Private clouds are owned and used only by a single organization
• Public clouds are privately owned but are available for public use
• Hybrid clouds have both private and public aspects
• Community clouds are owned by multiple organizations for their own private use

Cloud-based Applications

• Cloud storage enables access to synchronized saved files from any device
• Cloud-based applications move management to the cloud or e-mail and more
• PVirtual desktops provide a consistent workspace in the Cloud accessible from any device
• Virtual application streaming provides access to apps without installing them locally

Section 19: Portable Computing

Laptop Feature

• Ctrl + Function Keys! Extend Display, Turn of Touch Pad Airplane Mode, Econ Mode, Turn off Camera and more!
• Use settings in windows to control many aspects of portable computers
• Some laptops feature removable screens, turning laptop into a tablet
• Use a lock to secure a laptop when in a public space
• Docking stations and port replicators extend the capabilities of some laptops

Laptop Hardware Troubleshooting – The Tools

• Start laptop repair by reviewing manufacturer online information
• The iFixit website offers a lot of user-generated how-to guides
• Use caution on screws and connections; take pictures of the disassembly process(or dbl-sided tape!)

Laptop Hardware – Core Hardware

• Hard drive, RAM and Wireless adapters are sometime upgradeable.
• Start laptop repair by reviewing manufacturer online information
• The iFixit website offers a lot of user-generated how-to guides
• Use caution on screws and connections; take pictures of the disassembly process(or dbl-sided tape!)

Laptop Hardware – CPU and Motherboard

• CPUs are typically soldered on to the motherboard these days
• Start laptop repair by reviewing manufacturer online information
• The iFixit website offers a lot of user-generated how-to guides
• Use caution on screws and connections; take pictures of the disassembly process(or dbl-sided tape!)

Touring your Laptop Display

• Laptop monitors tend to be sealed systems. Typically, you will be replacing the entire unit as opposed to going in and fixing it.
• Replacing Laptop monitors usually mean replacing the wireless antenna and cameras all in one go
• Double check that you are re-attaching all of the connections when installing a new Monitor
• Spudgers and heat guns are essential monitor repair tools (if you decide to repair one instead of replacing it)

Section 20: Understanding Mobile Devices

What is a Mobile Device?

• By definition, a mobile device is a Single, Sealed Unit, Runs specific Mobile OS like Android or Apple OS (sometimes, but rarely Linux). They will always have Wireless Connectivity, Wi-Fi, and Bluetooth.
• Smartphones, Tablets, wearables, and GPS are all examples of mobile devices

Mobile Connections

• Mobile devices use wired or wireless connections
• Common wired connections: micro-USB, USB C, Lightning, and Thunderbolt
• Common wireless connections include NFC (Near Field Communication), Bluetooth, infrared and 802.11

Touring Android

• The Android desktop only shows the applications you choose
Notifications are seen by swiping down
• The Google play store is where Android users install applications
• You can change permissions for Apps If needed
• Android phones are associated with a google account; you can add accounts if desired

Touring iOS

• All applications appear on the home screen
• Swipe down for notifications and spotlight search, swipe up for control center
• The App store is where iOS users install applications
   you change app permissions in settings
• All iOS devices require an iCloud account

Virtual Reality

• Virtual reality (VR) is a complete virtualized environment
• VR will include a headset that detects head movements (tracking)
• Augmented reality (AR) places virtual objects in the real world

Section 21:  Care and Feeding of Mobile Devices

Maintaining Mobile Devices

• Two basic kinds of Phones CDMA(Code Division Multiple Access) GSM(Global System for Mobile communications)
• GSM – come with sim card CDMAs don’t. CDMAs don’t exist outside of America, CDMA’s Firmware needs to be updated
• Types of CDMA Updates – Baseband Updates, Broadband Updates, Radio Updates. These are all typically handled for you.
• Preferred Roaming List – an update that can impact the speed of your phone, connection speed and other performance related issues.
• International Mobile Subscriber Identity (IMSI) doesn’t exist on CDMA
• International Equipment Mobile identity (IMEI) *#6# to bring it up
• Remember to turn on Backups
• Host based Firewalls are super important on Android

Mobile Devices and E-mail

• Corporate Email Configuration – needs Email Address, Password, FQDN(Fully Qualified Domain Name) of SMTP server, Port number (usually 25), FQDN for IMAP server and port number
• Email setup on smartphone always means adding an e-mail account
• Most traditional e-mail servers use Encrypted port numbers
• S-MIME (old Tech)
• ProtonMail (new tech)

Mobile Synchronization

• Synchronization means to update two or more data stores so their information is identical
We Synchronize our devices to a desktop, to an automobile, or to the cloud
• Android syncs with Google Drive; iOS devices sync with iCloud
• Most browsers provide Synchronization as well
• We can also sync location, e-books, social media, and applications

Section 22:  Printers and Multifunction Devices

Laser Printers

The Laser Printing Process
1. Processing Phase – Jobs are received from the computer and stored in memory on Printer.
2. Charging Phase  – Primary corona charging – where a (negative) -600 to -400v charge is placed on the drum.
3. Exposing Phase – Lasers hit the drum, increasing the charge to about negative 150v, This creates areas of high and low charge.
4. Developing Phase – The Lasers form the images or words on the drum. The pickup rollers grab the papers, the separation pads insure only one piece at a time is picked up.
5. Transferring Phase – The paper is given a positive charge, the positively charged papers attract the negatively charged toner.
6. Fusing – then the toner is sealed on the paper with heat and pressure. An Anti-static device wipes the static from the paper.
7. Cleaning – Any residual tuner is cleared from the Drum
• Laser printer maintenance means replacing the toner cartridge and applying Maintenance Kits and running Calibration Tests.
• In color printers the process is repeated for each color on a transfer belt, then Transferred to the paper.

Inkjet Printers

•Inkjet printers use heat or mechanical process to push ink through the print heads to the paper
• Multifunction devices (MFDs) include printers, scanners, copiers and fax machines
• Inkjet maintenance means running cleaning routines for the nozzles, plus some form of calibration

Impact Printers (Dot Matrix)

• Impact printers strike an ink ribbon to write to paper
• Uses Impact paper
• Impact printers are very useful for printing on multipart forms
• Maintenance for an impact printer includes replacing the ribbon and keeping it clean

Thermal Printers

• Thermal Printers Heat Special Paper to create a printout
• Used for sales receipts, usually comes in rolls.
• Thermal printers can print to multipart (Thermal) forms
• Maintenance with thermal printers includes frequent paper changes and keeping the heating element clean

Installing a local Printer

• Installing a local printer means connecting to workstation via USB or (rarely) serial
• Device drivers enables the OS to work with the printer
• The Print spooler enables multiple print jobs to queue and ensures that they are printed in the order they are received

Sharing Printers

• Sharing a local printer over a network requires sharing enabled and a share name
• Security options enable local control over the print spooler
• To connect to a shared printer, add a printer but select the shared printer rather than a local printer

Installing Wireless and Cloud Printers

• Avoid sharing issues, Set it up as a Wireless Device.
• Check what 802.11 Standard your using.
• A wired network printer has an Ethernet NIC and plugs in directly to the network
• A wireless network printer requires configuration to get on an 802.11 network
• Wireless print utilities can help troubleshoot any connectivity problems
• Cloud printing enables mobile devices to print to a printer associated with an online account such as a Google account

Troubleshooting Printers

 • Unable to install printer – you don’t have administrative rights to install the printer. See your sys admin. Perhaps its off or not plugged int to ethernet.
• No connectivity – are you physically connected to it. Do you get any DHCP. Perhaps the device driver had just been updated or the network card on the printer is malfunctioning.
• Access Denied – Lacking the required account privileges. Elevate privileges or see Sys admin
• No display on printer – bad display, printer off, screen off
• Paper not feeding, paper jam – pick-up rollers, humidity, maintenance kits
• Low memory errors – laser printers use RAM, try reducing the resolution or buy more RAM
• Error Codes – look it up on the manufacturer website
• Garbled Characters on paper – Bad drivers, Corrupted files hitting the printer. Try hard reset, updating or rolling back drivers
• lines on paper – replace the drum and/or toner cartridge
• Wrong print color – out of ink, bad driver
• Print blank pages – out of ink, dead primary corona, bad drum
• Streaks – vertical streaks – inkjet issue. Clogged print head. Try do a head clean.
• Faded prints – low on toner, clogged jets, If its an impact printer the ribbon needs to be replaced
• Ghost images bad drum. Bad toner
• Creased paper – pickup rollers

3D Printing

• 3D printers melt some material (such as forms of plastic) in a pattern to create a 3D shape
• Use specialized software to create a 3D image
• The printing process requires preheating the various print elements. Such as the filament, extruder and bed.

Section 23: Securing Computers

Dealing with Threats

• Host-based security includes patching, anti-malware and a firewall
• Network-based security includes IDS(Intrusion Detection Systems), IPS[Intrusion Protection System] and firewalls
• UTM includes IDS/IPS, firewalls, anti-malware, available on the cloud