CompTIA A+ 1101 - 2.0 Networking Flashcards
SOHO
Small Office / Home Office
SMB
Server Message Block - Commonly used for File Sharing
Port 139 - (Pre Windows 2000)
Port 445
NAT
Network Address Translation.
It’s a way to map multiple local private addresses to a public one before transferring the information. Organizations that want multiple devices to employ a single IP address use NAT, as do most home routers.
NFC (Near Field Communication)
A very short-range communication method where a wireless signal is sent between two devices that are touching or nearly touching each other
424Kbps speed with 4cm range
Bluetooth
Bluetooth is an open wireless technology standard for transmitting data over short distances. It uses radio waves on a particular frequency for data transmission from device to device
3Mbps with 10 Meter Range
802.11ac
Wi-Fi 5
6.9Gbps with 100 Meter Range
8x DL MU-MIMO
RF of 5Ghz
802.11g
Legacy
54Mbps with 100 Meter Range
RF of 2.4Ghz
802.11a
Legacy
54Mbps with 50 Meter Range
RF of 5Ghz
802.11b
Legacy
11Mbps with 10 Meter Range
RF of 2.4Ghz
PAN
Personal Area Network
WAP
Wireless Access Point
WLAN
Wireless Local Area Network
FTP
File Transfer Protocol
A standard communication protocol used for the transfer of files from a server to a client.
Port 20 - For Data Flow
Port 21 - Controls the data flow
SSH
Secure Shell Protocol
SSH is widely used by network administrators to manage systems and applications remotely, enabling them to log in to another computer over a network, execute commands and move files from one computer to another.
Port 22
Telnet
Telnet is a network protocol used to virtually access a computer and to provide a two-way, collaborative and text-based communication channel between two machines.
Port 23
SMTP
Simple Mail Transfer Protocol
An Internet standard communication protocol for electronic mail transmission.
Port 25
DNS
Domain Name System
Phonebook of the Internet / Network
Port 53
DHCP
Dynamic Host Configuration Protocol
A network management protocol used on Internet Protocol networks for automatically assigning IP addresses and other communication parameters to devices connected to the network using a client–server architecture.
UDP Port 67 - For Servers
UDP Port 68 - For Clients
HTTP
HyperText Transfer Protocol
An application layer protocol in the Internet protocol suite model for distributed, collaborative, hypermedia information.
The set of rules for transferring files – such as text, images, sound, video and other multimedia files – over the web
Port 80
POP3
Post Office Protocol 3
An application-layer Internet standard protocol used by e-mail clients to retrieve e-mail from a mail server. (Outlook etc)
Port 110
Secure Port 995
NetBIOS
Network Basic Input Output System
A network service that enables applications on different computers to communicate with each other across a local area network. Mostly used for legacy app support now.
Port 137, 138 and 139
IMAP
Internet Mail Access Protocol
A method of accessing and storing mail on a mail server.
Port 143
SNMP
Simple Network Management Protocol
A networking protocol used for the management and monitoring of network-connected devices in Internet Protocol (IP) networks
Port 161 - SNMP Manager sends commands to Clients
Port 162 - SNMP Client sends a response to the Manager
LDAP
Lightweight Directory Access Protocol
The common use of LDAP is to provide a central place for authentication – meaning it stores usernames and passwords. (Active Directory)
Port 389
HTTPS
HyperText Transfer Protocol Secure
Used for secure communication over a computer network, and is widely used on the Internet. Encrypted using Transport Layer Security (TLS)
Port 443
RDP
Remote Desktop Protocol
A proprietary protocol developed by Microsoft which provides a user with a graphical interface to connect to another computer over a network connection
Port TCP 3389
MAN
Metropolitan Area Network
SAN
Storage Area Network
WAN
Wide Area Network
DMARC
Domain Message Authentication, Reporting and Conformance.
An email authentication, policy, and reporting protocol that builds on DKIM and SPF
DKIM
DomainKeys Identified Mail
An email authentication technique that allows the receiver to check that an email was indeed sent and authorized by the owner of that domain.
SPF
Sender Policy Framework
Lets you publish a DNS record of all the domains or IP addresses you use to send email.
Receiving email services check the record and know to treat email from anywhere else as spam.
Twisted Pair Cable
Twisted pair cabling is a type of wiring used for communications in which two conductors of a single circuit are twisted together for the purposes of improving electromagnetic compatibility.
Cat5
Cat5 cables can carry data, telephone and video signals and have a maximum recommended length of 328 feet (100 meters) and are “crimped” into Ethernet connectors.
Cat5 provides a throughput of 100Mbps
Cat5e is the latest iteration, with throughput of 1,000Mbps
Cat6
Cat6 cables can carry data, telephone and video signals and have a maximum recommended length of 328 feet (100 meters)
Cat6 has a throughput of 10Gbps.
Coaxial Cable
A coaxial cable is a type of shielded and insulated copper cable that is used in computer networks and to deliver cable TV services to end users. It was first commercially implemented in the early 1940s and is used for both baseband and broadband data communication services
Terminates with an RG-6 Connector
Shielded Twisted Pair Cable
Shielded twisted pair (STP) is a special kind of copper telephone and local area network (LAN) wiring used in some business installations. It adds an outer covering or shield that functions as a ground to ordinary twisted pair wiring.
Plenum
Spaces above / below rooms that allow for fire-retardent electrical cabling to be routed throughout the building.
Plenum Cables include Cat5, Cat6 etc…
Optical Cable
An optical cable transfers audio digitally, but instead of copper wire, light is used.
Fibre-Optic Cable
Fiber optics is used for long-distance and high-performance data networking
T568A - T568B
Twisted Pair Wiring Schemes
Cabling for commercial buildings, and between buildings in campus environments.
SMF
Single-Mode Fiber
Long Range Fiber Optic Cabling (up to 100km)
10Gbps +
Used for WAN’s and long distance cabling
MMF
Multi-Mode Fiber
Short Range Fiber Optic Cabling (up to 2km)
10Gbps +
Used for LAN’s and direct Hub to House connections
Fiber Optic Connector Types
Straight Tip (ST)
Subscriber Connector (SC)
Lucent/Local Connector (LC)
NIC
Network Interface Card
Switch
Core appliance of modern networks, connecting devices to one another in a LAN.
Hub
Obsolete multiport repeater replaced by the switch.
Would broadcast to all ports instead of requesting specific MAC address information, creating large slowdowns in network speed.
Repeater
Obsolete signal re-transmitter that would revitalise a long distance connection to prevent attenuation
Switches do this automatically in modern networks.
Attenuation
The loss of data over long distances (Example; if a Cat5 cable went further than 100 meters, the charge carrying that data would be exhausted and would dissipate)
Bridge
Obsolete.
Would divide networks into segments to reduce collision.
We now use a “managed switch” to achieve this as ports can be segmented/grouped.
PoE
Power over Ethernet
Unmanaged Switch
Universal Plug n Play, found in smaller networks (4 or 8 port switches) and embedded in most home routers
Managed Switch
Used within larger corporate networks by linking/daisy-chaining switches together
Can divide into virtual LANs.
- Can priotize certain types of traffic (VoiP gets priority by default)
QoS
Quality of Service
Spanning Tree Protocol
Eliminates bad/unresolvable requests over the network by destroying the data remnants after a period of time.
Port Mirroring
Mirrored/reflected information sent over the network and picked up by a monitoring device for network management.
MAC Address
Media Access Control Address
Otherwise known as the physical, or hardware address.
802.11n
Wi-Fi 4
150Mgbs with 70 Meter Range
4 x MIMO
802.11ax
Wi-Fi 6
9.6Gbps with 70 Meter Range
8 x DL / UL MU-MIMO
MIMO
Multiple Input/Output
MU-MIMO
Multi-User Multiple Input/Output
DL MU-MIMO
Downlink Multiple User, Multiple Input/Output
DL/UL MU-MIMO
Downlink/Uplink Multiple User, Multiple Input/Output
2.4Ghz
Longer Wavelength, Longer Range and propagates better through solids (BASE)
Increased risk of interference
Slower speeds than 5Ghz
Up to 14 Channels, with considerable overlap.
Channels 1, 6 and 11 can be used without interfering with one another.
5Ghz
Shorter range, less effective at solid surface penetration
Fast data rates and more individual channels
15 Individual channels with no overlap whatsoever (Meaning more WAN’s in a small environment and higher client device density)
ONT / FTTP
Optical Network Terminal / Fibre to the Premises
The point of entry for the ISP’s fibre network into your premises
WISP
Wireless Internet Service Providers
Delivering Internet by way of ground based wireless antenna technology, via Wi-Fi, 5G or other equipment.
Used in rural areas where wired network may not be possible.
TCP/IP
A suite of rules & protocols that are used to standardize data transfer between systems.
This is the main language used on the internet.
(IE; China and the US don’t talk the same language, but their machines do)
Divided into 4 layers
Application Layer
The layer of TCP/IP that is responsible for interaction utilizing ports.
For example; DHCP, FTP, SMTP, HTTP etc….
Transport Layer
The Layer of TCP-IP responsible for TCP & UDP.
Can be configured for speed and less security (UDP) or the opposite (TCP)
Internet Layer
The Layer of TCP/IP referring to IP addresses and their linkage
Link Layer
The Layer of TCP/IP referring to Ethernet and Wi-FI.
Otherwise known as the method of transport
Maximum number of hops before TTL (Time to Live) obliterates the data package
30
TCP
Transmission Control Protocol
Secure, reliable protocol that facilitates successful delivery at the cost of speed.
Connection-oriented, meaning it maintains acknowledgements from the destination to ensure delivery of data.
UDP
User Datagram Protocol
Speed focused protocol that prioitizes fast delivery of data over security.
Connectionless, meaning it doesn’t need acknowledgements from the target and can tolerate missing or out of order packets.
(A) Records
This DNS record type is for IPv4 Addresses and associates the hostname with an IP address.
You can modify the A record to change the host name -> IP Address resolution
(AAAA) Records
This DNS record type is for IPv6 addresses and associates the IP address with a hostname.
Hostname -> IPv6 Record
MX Record
Mail Exchanger record, this determines a name for the mail server (Not its IP Address)
FQDN
Fully Qualified Domain Name
WEP
A legacy Wi-Fi security protocol, since replaced in favour of WPA / WPA2
WPA / WPA2
Modern Wi-Fi security protocol that uses TKIP.
Developed to meet 802.11i standards.
UTM
Unified Threat Management
Single appliance/gateway that performs multiple security functions
Network Security Functions
Firewalls
Intrusion Detection Systems (IDS)
Anti-Virus/Anti-Malware solutions (SOPHOS, Symantec etc..)
Spam Gateways
Content Filters
Data Leak/Loss Prevention Systems (DLP)
SCADA / ICS
Supervisory Control and Data Aquisition / Industrial Control System
System of software and hardware elements that allows industrial organizations to: Control industrial processes locally or at remote locations. Monitor, gather, and process real-time data.
Eg; Oil & Gas Processing, Energy, Water & Waste….
PLC
Programmable Logic Controller
PLC’s are linked by a cabled network to actuators that operate valves, motors, temperature gauges and sensors.
HMI
Human-machine Interface
Output and configuration of a Programmable Logic Controller (PLC) is done by an HMI.
OT Network
Operational Technology Network
An embedded system network that is distinguishable from an IT network by its usage in industrial automation and isolation from the Internet.
Network Firewall
Inspects all traffic coming inline towards the LAN from external sources and intercepts depending on legitimacy.
Filters based on:
IP Address
Protocol ID/Type
Port
Host Firewall
Installed on host machines (standard end user device)
Inspects traffic coming into the host from external sources.
Filters based on:
IP
Port
Protocol
Software
Users
Services / Processes
MAC Filtering
Security feature for Firewalls, Switches and Access Points.
Can whitelist/blacklist devices based on MAC addresses, good for SOHO
Remote Desktop
Allows a user to connect to a desktop remotely via TCP port 3389
Can be configured to work from outside the company network.
Not enabled by default and needs configuring in Windows OS beforehand.
Remote Assistance
Allows a user to request help from a technician (often sidebarred in favour of 3rd party software like Bomgar, Teamviewer etc…)
Operates within the company network, doesn’t support external connections.
Enabled by default on Windows OS
RDPRA
Remote Desktop Protocol Restricted Admin mode
Helps to keep RDP sessions more secure by using encryption and constant background authentication.
SFTP
Secure File Transfer Protocol
Combining SSH administration and FTP, this a a secure method of transferring files on a network.
Authenticates using:
Username/Password, Kerboros, Host based, Public/Private key
VNC
Freeware RDP software for screen sharing that doesn’t include connection security, unlike commercial software like Teamviewer etc…
TCP Port 5900
Windows Editions that support RDP
Professional, Enterprise & Ultimate
Ping Loopback Command
Ping 127.0.0.1 to ping the computer itself
Netstat Command
Used to verify the ports that are in use.
the “-b” switch can associate running software with the ports they’re using.
Z-Wave
Wireless Protocol for Domestic IoT Technology.
Allows smart devices to connect and exchange control commands and data with each other.
ZigBee
2.4Ghz Wireless Protocol for Domestic IoT Technology.
Allows up to 65,000 smart devices to connect and exchange control commands and data with each other.
802.3af
Power over Ethernet (PoE) standard that provides up to 15.4w of DC power on each port.
802.3at
Power over Ethernet (PoE) standard (also known as PoE+ / PoE Plus) that provides up to 25.5w of power for Type 2 devices.
802.3bt
Power over Ethernet (PoE) standard (also known as PoE++ / 4PPoE) that provides two additional power types:
51w of power delivered to Type 3 devices
71.3w of power delivered to Type 4 devices
