CompTIA A+ (Core 1) Flashcards
POP3 (Name, port, description)
Post Office Protocol v3
tcp/110
Download/receive email to local email client (unsecure)
POP3S (Name, port, description)
Post Office Protocol v3 secure
tcp/995
Downloads/receive email to local email client (w/ Secure Socket layer settings)
IMAP4 (Name, port, description)
Internet Message Access Protocol v4
tcp/143
A newer email client protocol from POP3 and allows access to mail on a central server.
IMAP4S (Name, port, description)
Internet Message Access Protocol v4 Secure
tcp/993
IMAP4 w/ Secure Socket Layer settings
SMTP (Name, port w/+w/out authentication, description)
Simple Mail Transfer Protocol
tcp/25 (no authentication)
tcp/587 (authentication)
Transfer email between mail servers.
FTP (Name, port x2, description)
File Transfer Protocol
tcp/20 (active mode data), tcp/21 (control the comms)
Sends/receives files between systems
SSH (Name, port, description)
Secure Shell
tcp/22
Encrypted console access
Telnet (Name, port, description)
Telecommunication Network
tcp/23
Insecure console access
DNS (Name, port x2, description)
Domain Name System
udp/53, tcp/53
Convert domain names to IP addresses
HTTP (Name, port, description)
Hypertext Transfer Protocol
tcp/80
Web server communication
HTTPS (Name, port, description)
Hypertext Transfer Protocol Secure
tcp/443
Web server communication with encryption
RDP (Name, port, description)
Remote desktop protocol
tcp/3389
Graphical display of remote devices
NetBIOS N (Name, port, description)
NetBIOS Name service
udp/137
Register, remove and find Windows services by name
-Older version of SMB
NetBIOS D (Name, port, description)
NetBIOS Datagram service
udp/138
Windows connectionless data transfer
-Older version of SMB
NetBIOS S (Name, port, description)
NetBIOS Session service
tcp/139
Windows connection-oriented data transfer
-Older version of SMB
SMB (Name, port, description)
Server Message Block/Common Internet File System (CIFS)
tcp/445
Windows file transfers and printer sharing
-Newer version of NETBIOS
AFP (Name, port, description)
Apple Filing Protocol
tcp/548
Mac OS file transfer
SLP (Name, port x2, description)
Service location protocol
tcp/427, udp/427
Find Mac OS services by name
DHCP (Name, portx2, description)
Dynamic Host Configuration Protocol
udp/67, udp/68
Automate the IP address configuration process
LDAP (Name, port, description)
Lightweight Directory Access Protocol
tcp/389
Directory services
SNMP (Name, port, description)
Simple Network Management Protocol
udp/161
Gather metrics and manage network devices
What is TCP and what does it stand for?
Transmission Control Protocol - Connection oriented protocol + a reliable form of delivery.
- Recovers from error.
- Manage out -of-order messages/re-transmission.
- Receiver acknowledges info was received to sender.
- Flow control (Receiver manage how much data sent)
What is UDP and what does it stand for?
User Datagram Protocol - Connectionless protocol + unreliable form of delivery.
- No error recovery
- No reorder of data or transmission
- No acknowledgement from receiver when data is received
- No flow control
Which OSI layer does TCP/UDP take place in?
OSI Layer 4 - Transport layer
What is a repeater?
- Extends network connections for a specific topology
- Receives signal, regenerate and resend (No forwarding decisions)
- Goes into 1 connection and comes out another connection (i.e. Boosts copper/fiber connection, convert one network media to another etc.)
What is a hub?
- It is a multi-port repeater (traffic goes into 1 port and is repeated to every other port)
- Half duplex (2 devices can’t communicate concurrently)
- Becomes less efficient as network speeds increase/doesn’t scale when increasing network traffic
- Ethernet hubs operate @ 10/100 megabits
What is a bridge?
- A switch with 2-4 ports (forwarding decision based in software)
- Connects different physical network topologies (i.e. WAP = a bridge as wire ethernet > wireless)
- Distributes traffic based on MAC address
What is a switch?
- It is a bridge, but done in hardware.
- Allows for scaling and forwards traffic based on data link address
- Many ports/features and maybe power over ethernet
- Multi-layer switch (based on MAC address)
What is a unmanaged switch?
- Plug/play, fixed configuration, little integration with other devices
- Low price point
- No VLANs
What is managed switch?
- VLAN support (interconnect w/ other switches via 802.1Q)
- Traffic prioritization
- Redundancy support
- Port mirroring (Capture packets for analysis)
What is a router?
- Routes traffic between IP subnets
- Makes forward decisions based on IP address
- Sometimes are inside switches > called layer 3 switches
- Connects diverse network types on same router (i.e. LAN, WAN, copper, fiber)
What is a wireless access point (WAP)?
- A WAP is a bridge (Extends wired network onto wireless network)
- Makes forwarding decisions based on MAC address
- A wireless router = A router + WAP in a single device
What is a Wireless LAN Controller?
- Centralized management of WAPs
- Performance/security monitoring
- Configure/deploy changes to all sites
- Uses proprietary tech (i.e. Cisco)
- Can be cloud-based
What is a firewall?
- Filters traffic by port number (OSI Layer 4, TCP/UDP)
- Some can filter based on application
- Can encrypt traffic in/out of your network (VPN)
- Can proxy traffic (Sits in middle to intercept request and send/receives for you)
- Sits on the ingress/egress (enter/exit) of the network
What is a cable modem?
- Broadband network (i.e. Shaw)
- Transmission across different frequencies (5/2.4 Ghz)
- Data on the cable network (DOCSIS > Data Over Cable service interface specification)
- Multiple services (i.e. Data, voice, video)
What is a DSL Modem?
- DSL/ADSL = Asymmetric Digital subscriber line
- Uses telephone lines (RJ11) instead of cable lines of cable modems
- Called ADSL cuz download speed is faster than upload speed (asymmetric)
What is PoE?
- Power over Ethernet
- Power provided on an Ethernet cable (1 wire for both network/electricity)
What is EoP?
- Ethernet over Power, AKA PLC (Power line communication)
- Provides ethernet over power cables
802.11a (Frequency, Max MIMO stream, Max throughput per stream, max total throughput)
MIMO = Multi-input/output (multi-receivers to receive/send data)
Frequency: 5 GHz
Max MIMO streams: N/A
Max throughput (per stream): 54 Mbit/s
Max throughput (total): 54 Mbit/s
802.11b (Frequency, Max MIMO stream, Max throughput per stream, max total throughput)
Freq: 2.4 GHz
Max MIMO streams: N/A
Max throughput (per stream): 11 Mbit/s
Max throughput (total): 11 Mbit/s
802.11g (Frequency, Max MIMO stream, Max throughput per stream, max total throughput)
Freq: 2.4 GHz
Max MIMO streams: N/A
Max throughput (per stream): 54 Mbit/s
Max throughput (total): 54 Mbit/s
802.11n (Frequency, Max MIMO stream, Max throughput per stream, max total throughput)
Freq: 5 GHz or 2.4 GHz
Max MIMO streams: 4 MIMO
Max throughput (per stream): 150 Mbit/s
Max throughput (total): 600 Mbit/s
802.11ac (Frequency, Max MIMO stream, Max throughput per stream, max total throughput)
Freq: 5 GHz
Max MIMO streams: 8 MU-MIMO
Max throughput (per stream): 866.7 Mbit/s
Max throughput (total): ~6.8 Gbit/s
802.11 @ 2.4 GHz non-overlapping channels?
Channel 1, 6, or 11
RFID name/examples
Radio Frequency ID
- Anything that needs to be tracked via radar tech (i.e. animal/pet ID, access badges)
- Mostly 1 way communication
NFC name/examples
Near field communication
- 2 way wireless communication (builds on RFID)
- Ex. Cell phone credit card payments
IPv4 (bits, bytes, octet)
Internet Protocol v4 (xxx.xxx.xxx.xxx)
-Total = 32 bits/4 bytes (8 bits or 1 byte/octet x 4)
IPv6 (bits, bytes, octet)
Internet Protocol v6 (16x’s multiply by 8 sections)
-Total = 128 bits/16 bytes (16 bits or 2 bytes x 8 sections)
Ex. fe80::5d18:652:cffd:8f52 (Skip consec 0’s & replace w/ ::)
What are cable crimpers used for?
- Pinches the insulator so that it’s tightly wrapped around the wire
- Pushes down copper tips in connectors so that it makes contact with copper wires inside insulation (i.e. RJ45)
What are multimeter used for?
- Checks AC/DC in wall outlets/wires/batteries
- Continuity testing for cable connectivity, fuse status (if it still works), wire mapping (which pins are connected to which)
What are tone generator used for?
- One is connected to a wire and the other part touches wire to determine the beep
- Where does that wire go?
What are cable testers used for?
- Attaches each end of a wire into a device and identify missing pins/crossed wires from head to toe
- Once plugged, both devices will do a countdown flash for #’s in sync and if something isn’t working, there will be a discrepancy in light flash.
What are loopback plugs used for?
-Used to send traffic out a particular interface, loop them around and send it back into the same interface.
Cable Category 3 (Max Ethernet Standard/Distance)
Ethernet Standard: 10BASE-T (10 Mbit/s)
Distance: 100M
Cable Category 5 (Max Ethernet Standard/Distance)
Ethernet Standard: 100BASE-TX (100 Mbit/s), 1000BASE-T (1000 Mbit/s)
Distance: 100M
Cable Category 53 (enhanced) Max Ethernet Standard/Distance
Ethernet Standard: 100BASE-TX (100 Mbit/s), 1000BASE-T (1000 Mbit/s)
Distance: 100M
Cable Category 6 (Max Ethernet Standard/Distance)
Ethernet Standard: 10GBASE-T (10 Gbit/s)
Distance: 37-55M
Cable Category 6A (Augmented) - Max Ethernet Standard/Distance
Ethernet Standard: 10GBASE-T (10 Gbit/s)
Distance: 100M
What is UTP/STP?
UTP = Unshielded twisted pair STP = Shielded twisted pair
What does U, S, F stand for?
What is the general format?
U = Unshielded
S = Braided shielding (flexible)
F = Foil shielding (rigid)
General format = (Overall cable)/(individual pairs) TP
What is S/FTP and F/UTP?
S/FTP = Braided shielding (overall cable) + Foil shielding (individual pairs) F/UTP = Foil shielding (overall cable) + Unshielded twisted pair
568A Termination Standard? (1-8)
- Green/White
- Green
- Orange/White
- Blue
- Blue/White
- Orange
- Brown/white
- Brown
568B Termination Standard? (1-8)
- Orange/White
- Orange
- Green/white
- Blue
- Blue/white
- Green
- Brown/white
- Brown
Thunderbolt v3 throughput
40 Gbit/s
USB 3/3.1/3.2 throughput
5 Gbit/s, 10 Gbit/s, 20 Gbit/s
What is DB-9/RS-232 serial cable connector used for?
-Serial connection built for modem comms
Ex. Modems, printers, mice, networking
-Used for configuration port (Serial console interface)
SATA 2, 3, 3.2 throughput?
3 Gbit/s, 6 Gbit/s, 16 Gbit/s with 1 meter range
What is RJ11 connector used for?
Connecting a telephone or analog modem to your plain old telephone system (POTS)
What is RJ45 connector used for?
Wired Ethernet connection
What is RS232 connector used for?
Serial communication standard (i.e. Modems, printers, mice, networking, config port for firewalls/switches)
What is a BNC connector?
- Bayonet Neill-Concelman Connector
- Plug in and twist to lock
- Commonly used for coaxial cable connector
What is a F-connector?
- Cable television/modem connector
- A thin pin and then lots of twisting to secure it
What is the difference betwen eSATA and SATA for design?
- eSATA has ears on both sides with a rectangle in the middle
- SATA has a single ear on the side and a L shape in the middle
What is DRAM?
Dynamic Random Access Memory - The memory on the DIMM.
What is SDRAM?
Synchronous Dynamic Random Access Memory - Found on today’s modern computers.
-Synchronous with common system clock > Queue up one process while waiting for another (Speed advantage)
SDR vs DDR
Single Data Rate Memory - Pull 1 bit of data per 1 clock cycle. (6 clock cycle in total)
Dual Data Rate Memory - Pull 2 bits of data per clock cycle. (12 clock cycle in total)
What is even parity (RAM)?
- Adds up the bits (1/0s) for a total of 8 bits > If it is odd #, then add a parity bit (1) to ensure it’s even.
- Once parity bit has been added and transaction occurred inside the RAM, write back this info into storage device, but check first.
- If everything (including parity) = odd, then it’s a corrupt file.
SATA bandwidth throughput ? (What does AHCI stand for?)
- SATA is designed for hard drives (uses Advanced Host Controller Interface) to move drive data to RAM
- SATA revision 3 ~ 600MB/s.
M.2 SSD throughput? (What does NVMe stand for?)
Non-volatile memory express
- M.2 ~ 4 Gbyte/s or faster
- SSD may also use AHCI as well.
What are the 5 components that make up a hard disk drive? (Outside > Inside)
-Actuator > Arm > Head > Platter > Spindle
What is RAID 0?
- File blocks are split between 2 or more physical drives (Striping)
- High performance, no redundancy
- A drive failure breaks the array
What is RAID 1?
- File blocks are duplicated between 2 or more physical drives (Mirroring)
- High redundancy (Drive failure doesn’t affect data availability)
- Slow performance due to duplicating everything
What is RAID 5?
- File blocks are striped, along with a parity block (Stripe with Parity)
- Requires at least 3 disks
- Efficient use of disk space + high redundancy (data available after drive failure)
What is RAID 10?
- The speed of striping + redundancy of mirroring
- Best of both worlds (Requires at least 4 disks)
PCI vs. PCIe throughput?
PCI - Peripheral Component Interconnect (Parallel)
(133 MB/s - 533 MB/s depending on bus version)
PCIe - Communicates Serially
(250 MB/s - 4 GB/s per lane depending on version)
What does LGA stand for? Where do the pins go?
Land Grid Array - Pins go on the motherboard.
What does PGA stand for? What do the pins go?
Pin Grid Array - Pins on the CPU.
Mobo components using (12 v, 3.3 v)
12v- Fans, PCIe adapters, hard drive motors
3v - RAM slots, m.2 slots, logic circuits
What are the 7 steps of printing?
- Processing (Build entire page in memory)
- Charging (Prepare drum with a - electrostatic charge)
- Exposing (Write the image with the laser)
- Developing (Add toner to the charged areas of imaging drum)
- Transferring (Move the toner from the drum to the paper)
- Fusing (Heat/pressure)
- Cleaning (Remove excess toner)
What are the 7 steps of troubleshooting?
- Identify the problem
- Establish a theory
- Test the theory > Is it working?
- Create a plan of action
- Implement the solution
- Verify full system functionality
- Document findings
What is change management and the 6 steps associated with it?
- Plan for a change
- Estimate the risks associated with the change
- Have a recovery plan if change doesn’t work
- Test before making the change
- Document all of this and get approval
- Make the change
What kind of memory is BIOS stored in a regular PC?
ROM (Read-only memory)
What are the standard rotational speeds of a hard drive?
5,400, 7,200, 10,000 rpm
What is the standard voltage for AC in US?
110v to 120v (220v to 240v is sometimes used, but not the standard)
What is the standard voltage for AC in Europe?
220v to 240v
Which 2 SATA-based formats does a laptop SSD come in?
1.8 inch (m.2) and 2.5 inch
Which part of a computer is used with older display tech to convert DC power to AC power?
Inverter (Found in displays that uses CCFL - Cold Cathode fluorescent lamps)
What are the ranges of private IPv4 addresses?
- 0.0.0 – 10.255.255.255,
- 16.0.0 – 172.31.255.255,
- 168.0.0 – 192.168.255.255
When manually configuring TCP/IP settings on a computer in a SOHO network, what address should you enter as the default gateway address?
The internal address of the Internet router
Note: The default gateway address = the address a computer sends traffic to if it has no other route in its routing table.
A user who travels extensively with her laptop needs to protect sensitive data stored on her hard drive. Which feature of Windows Ultimate allows for encryption of the entire drive?
BitLocker
A user enters the Windows command line prompt to create a new directory. What is the command to accomplish this?
MD - Make Directory (or MKDIR)
What feature of the NIC allows for a powered down or sleeping PC to power on when a job is received?
Wake-on LAN
What utility can you use to eliminate any temporary files from your hard drive?
Disk cleanup
If your server in the networking room catches fire, how should you put out the fire?
Use a class C fire extinguisher
Who administers the SDS (safety data sheet)?
Note: SDS is used for guiding the disposal of computing devices.
OSHA (The Occupational Safety and Health Administration)
How can you tell how much of a surge can be handled by a surge suppressor?
Joule rating
What is a form of malware that has the ability to replicate without any intervention?
A worm
When someone is assigned only the rights/privileges necessary to do her job, this is referred to as___
Principle of least privilege
A user frantically calls you to obtain sensitive information like username/password, what is this fraudulent activity called?
Social Engineering
DVI cable adaptability
DVI-A = Analog
DVI-D = Digital
DVI-I = Digital or Analog
DVI -A/D = Digital AND Analog
What type of transmissions is allowed for DisplayPort and HDMI cables?
Digital audio/video
What are examples of mass storage device interfaces?
SATA, IDE/PATA, SCSI (Small computer system interface)
What does USB-to-Ethernet converter enable as a connectivity?
802.3 connectivity
What are the characteristic features of SAS(Serial Attached SCSI)? (Name 3)
- Serial interface
- Point to point connection
- Doesn’t require bus termination
What is the way to identify logical partitions on a SCSI hard drive?
LUN (Logical Unit Number)
What is SCSI ID used for?
Identifies physical device on a SCSI chain
What is the max allowable # of devices that can be attached to a parallel SCSI bus?
16 devices
What is the max allowable cable length of Parallel ATA (PATA) interface?
18 inches
What is the max # of devices that can be attached to a PC via a single PATA cable?
2
How many pin connectors for a PATA cable?
40-pin connectors
List 3 characteristics of PATA cable?
Cable consisting of 40 wires, 80 wires and ribbon cable
What does SATA revision 3.2 specify?
Max cable length = 1 meter and 16 Gbps data transfer rate
How many pins does the SATA interface specification define data cable connector consisting?
7 pins
What does POTS stand for and type of cable interface is required for the modem?
POTS = Plain old telephone service, RJ-11 is required
When a SIM is moved from one phone to another, all incoming calls will follow the SIM. What identifier is used for this feature?
IMSI (International Mobile Subscriber Identifier)
What is the important voltage to check for PCIE adapters?
12v
What protocol is the best choice for consolidating log files from all firewalls, switches and routers?
Syslog (System logging protocol)
What should be used to block all known malicious data from entering the network via the Internet?
Intrusion Prevention System (IPS)
What protocol is commonly used by Apple products to locate music, photos and other resources?
Bonjour
What is the difference in layout between LGA and PGA?
LGA = Pins on motherboard, PGA = Pins on CPU
What is the storage capacity of the following:
- CD-ROM
- DVD-ROM single layer
- DVD-ROM dual-layer
- Blue ray single layer
- Blue ray dual layer
CD-ROM = 700 MB DVD-ROM SL = 4.7 GB DVD-ROM DL = 8.5 GB Blu Ray SL = 25 GB Blu Ray DL = 50 GB
What is the most commonly used main memory for PC?
SDRAM (Synchronous Dynamic Random Access Memory)
What can be used with a passive adapter to connect a DisplayPort monitor?
DisplayPort is compatible with both HDMI and DVI-D.
What are the specs for a Multimode fiber? Single mode fiber?
Multimode fiber can be used to transmit 10 Gbit/s network signals over a distance of around 550 meters.
Single mode fiber = long distance over 80km
A mobile provider has remotely updated the list of available connections when phone is used outside of home service area. What describes this update?
Preferred Roaming List - Describes list of available services when the primary mobile provider’s network isn’t available.
What is IMEI used for?
IMEI - International Mobile Station Equipment Identity > Identifies a physical mobile device like a unique ID.
What does orchestration mean?
The orchestration process provides a method to completely automate the building/tearing down of cloud services.
What technology best provide health info for a hard drive?
S.M.A.R.T (Self-monitor, analysis and reporting tech) provide extensive metrics about health/potential errors of a hard drive.
What type of paper is used for pulling through via holes on the side of the paper?
Tractor paper = often used to pull pages through paper path of an impact printer.
What does MDM stand for and what does it do?
Mobile device manager - Provides centralized management for mobile devices like phones/tablets.
What can be used to disable the optical drive for all OS systems on a desktop computer?
BIOS
Where are UEFI BIOS configuration settings stored?
Hard drive
What are the max RAM per DDR?
DDR = 4GB per DIMM? DDR2 = 8 GB per Dimm DDR3 = 16 GB per Dimm DDR4 = 64 GB per Dimm
What is used as a connection for a SAS drive?
SAS (Serial Attached SCSI) drive uses a single point-to-point connection between the drive and controller/mobo.
What is the difference between Ad Hoc mode vs. Infrastructure mode?
Ad Hoc Mode (WLAN) - Decentralized type of network and wireless devices communicate directly with each other rather than using a bridge, like an access point.
- It is peer to peer level and doesn’t require infrastructure setup and administration.
- Security/performance (w/ scaling) is an issue, but if y’all trust each other, then its fine.
Infrastructure Mode (WLAN): Centralized wireless network and more common in organizations.
- Wireless devices communicate with a WAP and not with each other.
- WAP = layer 2 device and acts as a bridge between wireless and wired devices.