Comptia A+ 1001

 1.1 Laptop Hardware

 

Mobile Devices:

  • Most use an ssd, sshd, or magnetic drive
  • SSD 1.8 – 2.5 form factors
  • Laptop use so-dimm and and micro-dimm memory
  • Optical drives aren’t common
  • They have Mini pci and mini pci express for ram and peripherals
  • Video cards built into processor, most you can’t replace
  • Most laptops use LCD (Liquid crystal display)
  • DC jacks for energy
    • Ac adapters turn AC into DC
    • Input voltage is either 110 or 220
  • Laptops have lithium ion (LI-ion) batteries
  • Frame could be metal or plastic
  • Speaker are integrated 
  • System boards are built to fit and are proprietary to the laptop.
  • CPU is worse than desktop because of heat and energy issues
  • Wireless card allows the laptop to connect to a wireless connection. Bluetooth is a (Personal area network)
  • Cellular card (3g,4g,LTE) are not common
  • WiFi antenna, webcam, microphone, inverter, and digitizer/touch screen.
    • Wifi antenna at top of screen
  • TN – twisted nematic; fast response times
  • IPS – in-plane switching; good for mobile devices more expensive
  • LCD are backlight by CCFL ( cold cathode fluorescent lamps ) More power required
  • Are also backlit by LED
  • Dual Monitors with an HDMI cable. There is a function key for this
  • Wireless function turns off and on wireless connection
  • The Airplane mode function key toggles WiFi, Bluetooth, and cellular on/off, simultaneously.
  • Docking station in a business environment for connecting things
  • Port replicator a worse docking station



  • To the desktop, to the cloud, to the automobile
    • Android -> Google drive
    • Apple -> iCloud
    • Windows – > onedrive
  • SSO(Single sign on) which allows you to login into multiple things through one
  • S/MIME encrypted and digitally signed email
  • PRL (Preferred roaming list) update – refers to which cell towers for roaming – Get a PRL update by texting a number
  • PRI (Product release instruction) – settings for device configurations specific to the cell network
  • Usually come with os updates
  • Interface between mobile and radio
  • IMEI an address for your mobile device (15 digit)
  • IMSI described that user in and the network

 

1.2

  • LCD is common and is backlight by usually an LED
    • LCD have low power and are lightweight
    • Hard to see pure black
  • OLED (Organic light emitting diode)
    • Uses organic compounds
    • No backlight
    • Basically better than LCD besides power and cost. Hard to put into laptops



1.4 Mobile Devices

Tablets:

  • Single-Screen touch computers
    • IOS, Android, Etc.
    • Large than ~7 inches diagonal
  • Designed for touch input
    • Virtual keyboard, drawing interfaces
  • Application Support
    • Productivity, games, utility, etc.
    • Specialized apps
  • Media
    • Take pictures, watch movies

 

Smart Phones:

  • Mobile communication
    • Voice, email, text ,instant message, pictures, video
    • ~3.5 inches to 6 inches diagonal
  • Media Viewer
    • Music, movies, videos
  • Mobile APps
    • Maps, travel information
  • Other apps
    • Productivity, games, specialized apps, etc. 

 

Wearable Technology:

  • Smart watches
    • An extension your phone and body
  • Fitness monitors
    • Track heart rate, steps, sleep patterns, and more

 

Virtual Reality: 

  • Replaces reality with a computer-generated version
    • Input from the real world interacts with the virtual world
  • Many different Apps
    • Gaming
    • Industrial design
    • Art
    • Enhanced video and image viewing

 

Augmented:

  • Overlay a virtual augmentation with the physical world
    • The computer provides additional detail
    • Medical 
    • Travel
    • Gaming

E-reader:

  • Specialized device
    • Book Reading
    • Some music, some apps
  • Electronic paper
    • Black and white screen
    • Performs well in direct light
    • Exceptionally long battery life
  • Network access
    • Wifi, cellular

GPS:

  • In car navigation or non car
  • Requires a view of the sky
    • Need to receive GPS signal
  • Periodic updates required 
    • Over the air
    • Memory Card



Summary:

  • Tablets are less than 7 inches diagonal
  • Phones are 3.5-6 inches diagonal.
  • Phones have features that the tablet doesn’t
  • Virtual reality is used in gaming, industrial design, art, and media viewing
  • Augmented reality is used in medicine and traveling
  • E-reader is electronic paper and only consumes energy when turning page (lasts long)
  • GPS needs a view of the sky

1.5 Mobile Device connections

 

Micro-USB and mini-USB:

  • EU standardized on MIcro-USB
    • Common now worldwide
  • Older devices may use Mini-USB
    • Slightly larger

 

USB – C:

  • 24-pin double sided USB connector
    • Used for both hosts and devices
  • Acts as a USB 3.1 / USB 2.0 connections
    • Only the interface is different
  • Includes an analog audio option
    • Headset support through a 3.5 mm jack

 

Lightning Cable (from apple):

  • Apple proprietary
    • 8-pin digital signals
    • iPhone, IPad, Ipod Devices
  • Some advantages over Micro-USB
    • Higher power output for phones and tablets (faster charge)
    • Can be inserted either way
    • Simpler design, more durable

 

Tethering:

  • Physically connect a device to your mobile phone
    • Use the internet/data connection
    • Computer uses USB to connect
  • Enable internet access from almost anywhere
    • May require service or configuration by wireless carrier

 

Hotspot:

  • Turn your phone into a wifi hotspot
    • Your own personal wireless router
    • Extend the cellular data network to all of your devices
  • Dependent on phone type and provider
    • May require additional charges and data cost

 

Proprietary mobile interfaces:

  • Early mobile technology was all about cables
    • One cable for power
    • A completely different cable for data
  • Every manufacturer was different
    • Intentionally
  • The EU changed things
    • Common external power supply for all data-enable mobile phone sold in the EU

 

NFC (Near Field Communication):

  • Send small amounts of data wirelessly over a limited area
    • Built into your phone
    • Payment systems, transportation, in-person information exchange,
  • Access Token, identity “card”
    • Short Range with encryption support

 

Bluetooth:

  • High speed communication over short distances
    • Pan (Personal Area Network)
  • Connects our mobile devices
    • Smartphones
    • Tethering 
    • Headsets and headphones
    • Health monitors
    • Automobile and phone integration
    • Smartwatches
    • External speakers

IR (Infrared):

  • Included on many smartphones, tablets, and smartwatches
    • Not really used for file transfers and printing
  • Control your entertainment center
    • Almost exclusively IR

 

Summary:

  • Micro-USB is standardized and Mini – USb still exists
  • USB-C (24 pin) acts as a USB 3.1 and 2.0 connection. Has audio 3.5 mm audio
  •  Lightning cable (8 pin) is apple proprietary. Has faster charge, can be inputted both ways, and simpler.
  • You can connect a phone or computer with wifi to other devices to enable wifi. This is done through usb and may require configuration by wireless carrier
  • A hotspot extends cellular data to all of your devices, might have extra charge from ISP
  • NFC (Near Field communication). Send info wirelessly over a close area. Used commonly in payment systems. Has encryption
  • Connects to your mobile devices. Has high speed communication over short distances a PAN (Personal Area network)
  • IR (Infrared) On many devices and can be used to control your entertainment center

 

Mobile Device Accessories

Headsets:

  • Hands-free audio
    • Earphones and microphone
  • Wired
    • Connects to 3.5mm TRRS(Tip Ring Ring Sleeve) connectors
    • Tip-Ring-Ring-Sleeve
    • Analog audio jack
    • Ihpone can use lightning port
  • Wireless
    • Bluetooth headsets

Speaker:

  • Mobile audio
    • Battery Powered
  • Wireless connection
    • Bluetooth link
  • Stereo sound
    • Small package

 

Gamepad:

  • Gaming console feel
    • Mobile phone or tablet
  • Connect with bluetooth
    • Wireless connectivity

 

Extra Battery packs / battery chargers:

  • Power is key
    • And in short supply
  • Swappable battery pack
    • Carry an extra or two
  • External USB Chargers
    • Phones and Tablets
    • And any other USB devices

 

Protective covers:

  • Screen protector 
    • Avoid Scratches 
    • May be difficult to install
  • Device protector
    • Wrap the entire device
    • Waterproofing options are available
    • Can create problems for docking stations and wireless chargers

 

Credit card readers:

  • Phone or tablet becomes a point of sale terminal
    • Connections to audio/mic TRRS jack, lightning connector, or bluetooth
    • Great for small and mobile businesses
  • Uses the internet link for approval
    • Immediate feedback
  • Additional features
    • Email Receipts
    • Sign with your finger

 

Memory / microSD:

  • Increase storage capacity of smartphone or tablet
    • Common on Android Devices
    • Not available on iOS devices
  • MicroSD cards
    • Small form factor
    • Almost too small
    • Increasing capacities.

 

Summary: 

  • Headsets are hand free audio. They connect with 3.5 mm TRRS (Tip ring Ring sleeve ) connectors. Apple can use lightning .
  • Speakers are battery powered. Can have wireless connection and let off stereo sound.
  • Extra battery packs for extra energy. 
  • Protective covers to prevent damage. Can be waterproof and might interfere with 
  • Credit card readers can connect to audio/mic TRRS jack, lightning connector, or bluetooth.
  • Memory / microsd. Common on android devices not available in iOS. MicroSD cards are small and increase capacity. 

 

Mobile Device Connectivity

 

Wireless / Cellular Data Network

  • Your phone has internet connections
    • Use your mobile provider network
    • Take advantage of this connectivity
  • Hotspot
    • Turn your phone into a wifi router
    • You may have to pay extra phone charges
    • Other devices connect to your phone via wifi
  • Tethering 
    • Anchored to your mobile device
    • Connect your laptop via USB or Bluetooth
    • Single connections
    • May require additional services from phone provider
  • Airplane Mode
    • One Button Turns off all radios
      • Cellular, Wifi, Bluetooth, NFC.
    • You can re-enable individual features without enabling cellular features
      • Useful when the airplane has Wifi
  • Enable and disable cellular, WIFI, and bluetooth independently
    • Airplanes, conserve battery
  • iOS 
    • Settings
    • Quick access from the control center
  • Android
    • Settings / wireless & network settings

 

Bluetooth

  • Short-range personal area network (PAN)
    • About 10 meters
  • Connect different devices
    • Mouse, keyboard, headset, computer, automobile, speakers
  • Once paired, devices work together
    • Connect and disconnect automatically

 

Bluetooth Pairing process:

  • Enable Bluetooth on both devices
    • Android and iOS: Settings / Bluetooth
  • Set devices to discoverable mode
    • May require key sequence on Bluetooth device
  • Select discovered Device
    • Many devices may appears
  • Enter or confirm PIN
    • Should be the same on both devices. 
  • Test connectivity
    • Devices should now communicate

 

Your phone is a radio:

  • Baseband radio processor
    • A network interface for you radio
    • This isn’t wifi or bluetooth
  • Has its own firmware and memory
    • Quite proprietary
  • Real-Time operating system
    • Everything happens very quickly as needed
  • The firmware can be updated
    • Over the air (OTA)
    • Invisible to the end the user. 

 

Phone Updates:

  • PRL updates
    • Preferred roaming list
    • CDMA networks (i.e, Verizon, Sprint)
    • Allows your phone to connect to the right tower
    • Can be updated over the air 
  • PRI updates
    • Product release instructions
    • Radio settings – ID numbers, network codes, country codes, etc.
    • Also updates over the air 

 

IMEI and IMSI:

  • IMEI
    • International Mobile Station Equipment identity
    • Identifies a physical mobile device
    • Every phone has a different IMEI
    • Can be used to allow or disallow access
  • IMSI
    • International Mobile Subscriber Identity
    • Identifies the user of a mobile network
    • Can we provisioned in the SIM card
      • Swap the SIm to move between phones



VPN:

  • Turn your phone into a VPN endpoint
    • Important for secure communication
  • Integrated into the phone OS
    • No additional software required
  • May require some additional setup
    • Detailed configuration settings

 

Configuring Email on Mobile devices

 

Email Configurations

  • Retrieving Mail
    • POP3, IMAP
  • Sending Mail
    • SMTP
  • Corporate email
    • Microsoft exchange
  • Integrated providers
    • iCloud, Google, exchange online, yahoo. 

 

Sending Emails: POP3

  • Post office Protocol 3 (POP3)
    • Used for downloading mail to local mail client
    • Downloads and optionally deletes from server
  • Configuration information
    • Name of POP3 Server
    • Username and password
  • Network ports
    • Defined by your mail provider
    • POP3: tcp/110
    • SSL (Secure Socket Layer) settings – POP3S: tcp/995

 

Retrieving mail messages:

  • Internet Message Access protocol (IMAP4)
    • Access mail on central server
    • Mail is usually stored on the server
    • Supports folders and server-side searching
  • Configuration information
    • Name of IMAP server
    • Username and password
  • Network ports
    • Defined by your mail provider
    • IMAP: tcp/143
    • SSL (Secure Socket Layer) settings – IMAPS: tcp/993

 

Sending email: SMTP:

  • SMTP
    • Simple Mail Transfer protocol
  • Send mail from a device to a mail server
    • Or between mail servers
    • You usually must send from a  local or trusted device
  • Authentication usually required
    • May be different credentials than the incoming mail
  • Port numbers
    • SMTP (no authentication, basically unused): tcp/25
    • SMTP with authentication: tcp/587

 

Microsoft Exchange:

  • Enterprise email
    • Not a service for the home
  • More than just email
    • Contacts, Calendars, Reminders.
  • Integrates with mobile device database
    • Integrated contacts, and calendars, etc. 
  • Configuration options
    • Email, server, domain, username, password
  • Integrated message encryption with S/MIME
    • Secure/Multipurpose internet Mail extension
    • Encrypt and digitally sign

 

Commercial Email Providers:

  • Gmail
    • Google email, splits inbox into tabs, IMAP4, POP3
  • Exchange Online (hosted email)
    • IMAP4 and POP3 support
  • iCloud Mail
    • Apple Mail, IMAP4 support only
  • Yahoo Mail
    • IMAP4 and POP3 support

 

Mobile device synchronization

 

Synchronizing your data

  • No single desktop
    • Many different devices
  • Complete Mobility
    • Access anything from anywhere
  • Many different types of data
    • Email, calendar, apps, etc.
  • All devices must stay synchronized
    • Most of it is invisible to us
  • Mutual Authentication
    • The client and server must authenticate with each other
  • Common Data types that are synced:
    • Contacts
    • Applications
    • Email
    • Pictures, music ,video
    • Calendar
    • Bookmarks
    • Documents
    • Location Data
    • Social media data
    • eBooks 
    • Passwords
  • Are all shared between our mobile devices. 

 

Synchronize to the cloud:

  • Completely hands-off
    • No physical cables, no local files
    • May be integrated into your exchange or email
    • Choose provider network and/or WIFI
  • Apple iOS
    • Sync all data types to iCloud
    • Complete backup and recovery
  • Android
    • Configure your google account

 

Synchronize to the desktop:

  • Application requirements
    • OS and disk space
  • Operating System
    • Mac, Windows
    • Relatively Modern version
  • Memory
    • Relatively minimal
  • Storage Space
    • Enough to store backups, video, pictures
    • You’ll need quite a bit
  • iOs
    • Apple Itunes – sync everything in the phone
    • Creates full backups on the computer
  • Android
    • Sync online with google
    • Use third-party apps like doubleTwist to transfer movies and music

 

Synchronize to the automobile:

  • Connect to your automobile over bluetooth or wired cable
    • Extend the phone functionality into the vehicle
  • Display maps, control, phone calls, play music
    • Big display screen, keep hands on the wheel
  • iOS CarPlay, Android Auto
    • Synchronizes contact information, music and other details
    • Shares phone information in real time
    • This could be a security issue in a rental car or shared vechile

 

Synchronization Connections

  • iOS
    • USB – Proprietary
      • 30-pin
      • 8-pin lightning
    • USB – C
      • 802.11 wireless
      • Mobile network
    • Android
      • USB Micro-B
      • USB-C
      • 802.11 wireless
      • Mobile network



Introduction to IP

 

A series of moving vans

  • Efficiently move large amount of data
    • Use a shipping truck
  • The network topology is the road
    • Ethernet, DSL, cable system
  • The truck is the internet protocol (IP)
    • We’ve designed the roads for this truck
  • The boxes hold your data 
    • Boxes of TCP and UDP
  • Inside the boxes are more things
    • Application information

 

TCP and UDP:

  • Transported inside of IP
    • Encapsulated by the IP protocol
  • Two ways to move data from place to place
    • Different features for different applications
  • OSI Layer r4
    • The transport layer
  • Multiplexing
    • Use many different applications at the same time
    • TCP and UDP

 

TCP – Transmission Control Protocol:

  • Connection-oriented
    • A formal connection setup and close
  • “Reliable” delivery
    • Recovery from error
    • Can manage out-of-order message or retransmission
    • TCP will give data and the receiver will send back an acknowledgement of receiving it. If it get an “ack” back it knows that it didn;t send
  • Flow control
    • The receiver can manage how much data is sent

 

UDP – User datagram Protocol:

  • Connectionless
    • No formal open or close to the connections
  • “Unreliable” delivery
    • No error recovery
    • No reordering of data or retransmissions
  • No flow control
    • Sender determines the amount of data transmitted

 

Speed Delivery:

  • The IP delivery truck delivers from one (IP) address to another (IP) address
    • Every house has an address, every computer has an IP address
  • Boxes arrive at the house / IP address
    • Where do the boxes go?
    • Each box has a room name
  • The Port is written on the outside of the box
    • Drop the box into the right room
  • A room might be labeled port 80 which is where all the port 80 boxes go

 

Lots of Ports:

  • IPv4 Sockets
    • Server IP address, protocol, server application port number
    • Client IP address, protocol, client port number
  • Non-ephemeral ports – permanent port numbers
    • Port 0 through 1,023
    • Usually on a server or service
  • Ephemeral ports- temporary port numbers
    • Ports 1,024 through 65,535
    • Determined in real-time by the client

 

Port numbers:

  • TCP and UDP ports can be any number between 0 and 65,535
  • Most servers (services) use non-ephemeral (non-temporary) port numbers
    • This isn’t always the case
      • It’s just a number
  • Port numbers are for communication not security
  • Service port numbers need to be “Well known”
  • TCP port numbers aren’t the same as UDP port numbers

 

Ports on the Network:

  • Web server – TCP/80
  • VoIP server – UDP/5004
  • Email server – tcp/143

 

Common Network Ports

 

FTP – File transfer Protocol:

  • tcp/20 (Active mode data),
  • tcp/21 (control) ← the one you should focus on remembering
    • Transfers files between systems
  • Authenticates with a username and password
    • Some system use a generic/anonymous login
  • Full -featured functionality
    • List, add, delete, etc. 



SSH – Secure Shell:

  • Encrypted communication link – tcp/22
  • Looks and acts the same as telnet

 

SMTP – SImple Mail Transfer Protocol:

  • SMTP – Simple Mail transfer protocol
    • Server to server email transfer
    • tcp/25
  • Also used to send mail from a device to a mail server
    • Commonly configured on mobile devices and email
  • Other protocols used for clients to receive email
    • IMAP, POP3



DNS – Domain Name System:

  • Converts names to IP addresses – udp/53
  • These are very critical resources
    • Usually multiple DNS servers are in production

 

HTTP and HTTPS:

  • Hypertext transfer protocol
    • Communication in the browser
    • And by other applications
  • HTTP is in the clear and HTTPS is encrypted
    • Supported by nearly all web servers and clients
  • HTTP: tcp/80
  • HTTPS: tcp/443

 

POP3 / IMAP:

  • Receive emails from an email server
    • Authenticate and transfer
  • POP3 – Post office protocol version 3
    • Tcp/110
    • Basic mail transfer functionality
  • IMAP4 – Internet Message Access protocol v4
    • tcp/143
    • Includes management of email inbox for multiple clients

 

RDP – Remote Desktop Protocol:

  • Share a desktop from a remote location over tcp/3389
  • Remote desktop services on many windows versions
  • Can connect to an entire desktop or just an application
  • Clients for Windows, macOS, Linux, Unix, Iphone, Android, and others. 

 

SMB – Server Message Block:

  • Protocol used by Microsoft Windows
    • File sharing, printer sharing
    • Also called CIFS (Common internet file system)
  • Using NetBIOS over TCP/IP
    • udp/137 – NetBIOS name services (nbname)
    • udp/138 – NetBIOS datagram services (nbdatagram)
    • tcp/139 – NetBIOS session service (nbsession)
  • Direct over tcp/445 (NetBIOS – less)
    • Direct SMB communication over TCP without the NetBIOS transport

AFP (Apple File Protocol):

  • File services in macOS
    • tcp /548
  • Works with SLP (Service Location Protocol)
    • tcp/427 and udp/427
    • Populate the list of available devices
  • File management 
    • Copy, move, delete file

 

DHCP – Dynamic host configuration protocol:

  • Automated configuration of IP address, subnet mask and other options
    • udp/67, udp/68
    • Requires a DHCP server
      • Servers, appliances, integrated into a SOHO router, etc.
  • Dynamic / pooled
    • Ip addresses are assign in real-time from a pool
    • Each system is given  lease and must renew at set intervals
  • DHCP reservation
    • Addresses are assigned by MAC address in the DHCP server
    • Quickly manage addresses from one location

 

LDAP:

  • LDAP (Lightweight directory access protocol)
    • tcp/389
  • Store and retrieve information in a network directory
    • Commonly used in the microsoft active directory. 

 

SNMP – Simple Network Management Protocol

  • Gather statistics from network devices
    • Queries: udp/161
    • Traps: udp/162
  • V1 – The original
    • Structured tabales
    • In-the-clear
  • V2 -A good step ahead
    • Data type enhancements
    • Bulk transfer
    • Still  in-the-clear
  • V3 – A secure standard
    • Message integrity
    • Authentication
    • Encryption

 

Table of all ports

Network Devices

 

Network Interface Card (NIC)

  • The fundamental network device
    • Every device on the network has a NIC
    • Computer, servers, printers, router, switches, phones, tablets, cameras, etc
  • Specific to network type
    • Ethernet, WAN, wireless, etc.
  • Often built-in to the motherboard
    • Or added as an expansion card
  • Many options
    • Single port, multi-port, copper, fiber




Repeater 

  • Receive signal, regenerate, resend
    • No forwarding decisions to make
  • Common use
    • Boost copper or fiber connections
    • Convert one network media to another
    • Extend wireless network reach

 

HUB (Old)

  • “Multi-port repeater”
    • Traffic going in one port is repeated to every other port
  • Everything is half duplex
  • Becomes less efficient as network speed increase
  • 10 mb / 100 mb
  • Difficult to find today

 

Bridge (Old):

  • IImagine a switch with two to four ports
    • Makes forwarding decisions in software
  • Connects different physical networks
    • Can connect different topologies
    • Gets around physical network size limitations / collisions
  • Distributes traffic based on MAC address
  • An example of a modern bridge is a wire access point
    • Bridges wired ethernet to wireless

 

Switches (New bridge):

  • Bridging done in hardware
    • Application-specific integrated circuit (ASIC)
    • Forwards traffic based on data link address
  • Many ports and features
    • The core of an enterprise network
    • May provide Power over Ethernet (PoE)
  • Multilayer switch
    • Includes routing functionality. 



 

Unmanaged Switches

  • A very plug and play type system, with very little customization
  • Fixed configuration 
  • No management protocol, very little integration
  • Not costly

Managed Switches

  • VLAN support
    • Interconnect with our switches via 802.1Q
  • Traffic prioritization
    • Voice traffic gets a higher priority
  • Redundancy support
    • Spanning Tree Protocol (STP)
  • External management
    • Simple network management protocol (SNMP) 
  • Port mirroring
    • Capture Packets

Routers

  • Routes traffic between IP subnets
    • Makes forwarding decisions based on IP address
    • Routers inside of switches sometimes called “layer 3 switches”
  • Often connect diverse network types
    • LAN, WAN, copper, fibers

Wireless access point (WAP)

  • Not a wireless router
    • A wireless router is a router and a WAP in a single device (They could be combined)
  • WAP is a bridge
    • Extends the wired network onto the wireless network
  • Makes forwarding decisions based on MAC address

Wireless LAN controllers

  • Centralized management of WAPs
    • A single “pane of glass”
  • Management functions
    • Deploy a new access points
    • Performance and security monitoring
    • Configure and deploy changes to all sites
    • Report on access point use
  • Usually a proprietary system
    • The wireless controller is paired with the access points
  • Can also be cloud based
    • Manage the console from anywhere

Firewalls

  • Filters traffic by a port number
    • OSI layer 4 (TCP/UDP)
      • Some firewalls can filter based on the application
  • Can encrypt traffic into/out of the network
    • Protect your traffic between sites
  • Can proxy traffic
    • A common security technique
  • Most firewalls can be layer 3 devices (routers)
    • Usually sits on the ingress/egress of the network