CompTIA A+ (Anki) 2 Flashcards
What are the seven layers of the OSI model
Physical Data Link Transport Session Presentation Application
operate at the (lowest layer), layer 1 of the OSI model. This is the physical layer
There is no progoramming or intelligence built into it
It is a device that is used to connect several computers together
Any signal that is received on it is copied to all other ports
Hubs
The two types of Hubs are
active and passive
Acronym to remember the OSI model
People Do Not Touch Sexy Pamela Anderson
_ hubs include the ability to regenerate and boost the signal (repeating) before sending to other ports
can be used to extend the length of a network
Active
__ hubs are simply a physical connection point for computers
not responsible for amplifying or regenerating signals
cannot be used to extend the length of a network
Passive
operate at layer 2 of the OSI model
They are aware of address but only physical ones
ex. Mac Address
Bridges
The key functions of __ are
join similar topologies (ex. connect 2 ethernet connections)
Divide network segments into multiple collision domains
Isolate network traffic
Bridges
examine layer 2 header information from incoming packets
Based on this information, they forward the packets to a specific port
-this improves performance and reduces overhead
Switches
The advantages of __
Increases available network bandwith (becuase there are fewer packets on the network)
Increases network performance
-helps regulate the flow of traffic
-reduces collisions
Increases security (aware of address, packets that are not intended for it do not go there)
Switches
The disadvantages of __ are
Cost
-more expensive
can be difficult to troubleshoot (have to identify which ports, if two systems cannot communicate
Devices can be spoofed
Proper design and configuration is needed
Switches
The two categories of switches are __
managed and unmanaged
The __ Switch category is
often reffered to as an “intelligent switch”
has its own IP address and configuration interface
typically connected using special software or a dedicated management port
managed
the __ Switch category is
a device that performs switching without any user intervention
cannot control the functions of this type of switch
can often be more cost effective for smaller deployments
Unmanaged
__ are intelligent devices used to determie the best path for transmitting data between networks
Routing tables are used to store network addresses
Network addresses represent the routes that are available
Can transmit data across multiple networks
-large networks can be divided into smaller IP subnet
-each subnet is still a different network
Routers
__ operate at layer 3 (network layer) of the OSI model
Can support various network types
LAN
WAN
copper
fiber
can route the traffic appropriately as long as its run on TCP/IP
Routers
__ connect multiple networks together, unlike a swich or hub
do not forward broadcasts
-Broadcaset domains are broken up
Determine the best route to the destination based on
-distance (how many routers will be crossed)
-congestion (how much traffic is on given on a route)
Routers
__ are any point that enables users to access a network
commonly used when referencing a wireless access point
-eg. an access point that enables users to connect over wireless
Access points
___ and ___ operate at the physical layer (layer 1) of the OSI model
designed to improve signal range and strength by amplifying any signal they recieve
-can extend range of wifi signal on router
-can operate wirelessly or with wire
eg. used at airports
Repeaters and extenders
__ is how PCs connect to a swith via a NIC
Can be wired or wireless
PC Network Interface Card (NIC)
Network devices require at least one interface
__ is your interface
can be hard wired or modular
-modular is a card and can be replaced in motherboard easily
-hardwired means it is physically soldered onto the motherboard
NIC
__ are hardware devices used to connect to a remote network or the internet
Sends and recieve data
-telephone line
-cable line
Modems
__ is internet connection established using a modem and standard telephone line
Modems dial into the ISP to establish an internet connection
Slow speeds
-Maximum of 50 Kpbs (kilobits)
ex. AOL
Dial-up modem
__ was a popular method for transferring digital signals over standard telephone lines
are used to connect to a DSL ISP
-has suspended dial-up modems
certain models have built in wifi capabilities
Digital Subscriber Line (DSL)
__ are hardware devices that use coax cable tv lines to provide high speed internet access
-always on connection
fast data transfer rates
cable modems
__ is a fancy term for being neat and organized in office. You bundle all cables together.
-ties/grommets
cable troughs
heat shrink
It is for safety and aesthetics
-labelling
ties/clips
floor covers
Structured cabling
__ are mounted hardware assemble containing multiple ports
Used in a LAN to house multiple cable connections
Ports are used to connect/manage LAN cables
-Incoming and outgoing
Like an extension cable
a mean to centralize all cable connections and then connects to switch
Patch Panels
__ panels are based on the number of ports they contain
12-port
24-port
48-port
Patch
\_\_ have different cable specifications Cat5E Cat6 Cat6A Cat 7 they are different transmission specification for what we call standard Ethernet networks
Patch panels
__ are metal frame chasis that stack and categorize different networking components
-patch panels
-switches
-routers
Patch cords can be used to connect a patch panel to to a network switch
Network Racks
PoE
Power over Ethernet
__ is a technology used for wired Ethernet LANs that enables electrical current to be carried over data cables
-alternative to power cord
commonly used when implementing wireless access points in remote locations that do not have power outlets
ex. ceilings
PoE
\_\_ is also referred to as "next generation PoE Powerful enought to support kiosks terminals LED lighting security card readers security cameras
IEE 802.3bt
__ is a technology used to transmit data using common electrical wiring
To function properly, an electrical outlet and an ethernet over power adapter are required
-both devices must be on the same electrical circuit
Ethernet over power
__ is ideal when it is not possible to run cables for a network connection
-considered an alternative to Wi-fI
Simple setup
-plug in devices and negotiate the connection
-eg. simply press the button on the side of the device
Ethernet over power
__ are
hardware or software bases
allow or deny a connection based on rules
Packet filters use rules based on IP addresses and ports
Stateful filters maintain session state information
-keeps track of everything that happend between two endpoints (like recording a phone call)
help protect against outside threats like hackers or intruders
Firewalls
__ are
specialized network appliance
placed between network and untrusted network
-between internal LAN and internet
configure port and IP address rules
-can allow what ports you want can go through firewall
Can act in various roles
-conent filter
-VPN concentrator
-Honeypot (a setup or trap for attacker) but there is nothing there
Hardware firewalls
\_\_ is usually run on a host as a application in small office or home computer port based control internet access, per application If operating system becomes compromised, so does the firewall Make sure is kept up to date
Software firewall
__ can be part of a firewall or a separate device
Analyze packets and allows or denies request based on rules you set up
Common filters include executables, emails or websites
Content filters
__ can gather information from wireless access points known as backhaul
communication is tunnelled back to the controller
-control-plan (represents the instructions)
-Data-plane (the traffic)
Cloud-managed wireless LAN
- access points connect to a virtual controller
- -controller is typically located in a public cloud
Cloud-based network controls
In NIC properties, in a __ duplex you can send and receive information
full
In NIC properties, a __ duplex is when we have to take turns. I can send but then you have to listen and vise versa
ex. standard phone call
half
SSH uses port
22
HTTP uses port
80
Telnet uses port
23
SMTP uses port
25
POP3 uses port
110
HTTPS uses port
443
DNS uses port
53
OSI
Open Systems Interconnect
The __ has 7 layers
provides a standard model for all network communication
allows manufacturers and developers to create devices and applications without needing proprietary programming
OSI model
is responsible for connecting the networks together
router
the __ is responsible for connecting computers
switch
operate on the 3rd layer of the OSI model (networks)
operate on logical (it can be changed) addresses
eg. IP address
primary function is to connect your network to the internet
Some models include extra data ports for switching
-known as layer 3 switches (router and switch in same physical device)
Always have at least 2 interfaces
-one interface has a public IP address assigned by your ISP and provides internet connectivity
-One interface has a private address assigned by default that connects to the internal networ
Routers
operate at the 2nd layer of the OSI model (data link)
operate on physical address (does not change)
eg. MAC (Media Access Control) address
primary function is to connect computers or other devices together
All devices connnected to the same switch can communicate with each other with minimal or no configuration
have a varying number of data ports depending on needs
-from 4 to 32 for most SOHO networks
switches
