Networking Flashcards
the principal set of digital message formats and rules for exchanging messages between computers across a single network or a series of interconnected networks (how data packets move through a network)
Internet Protocol
a logical numeric address that is assigned to every single device that is part of a TCP/IP-based network
IP Addressing
What is the goal of an IP Address?
to uniquely identify every node on the network; can change with time in the same network
How many bits does IPv4 addressing have?
32 bits
The first 3 numbers of an IPv4 address generally represent this
Network ID
The last number of an IPv4 address represents this
Host ID
used to determine what subnet a host is on; is this host on our network or another network
Subnet mask
IPv4 Class A addresses are within this range
The first octet is 1-127
IPv4 Class B addresses are within this range
128-191
IPv4 Class C addresses are within this range
192-223
IPv4 Class A subnet masks generally have how many octets used?
1 (255.0.0.0)
IPv4 Class B subnet masks generally have how many octets used?
2 (255.255.0.0)
IPv4 Class C subnet masks generally have how many octets used?
3 (255.255.255.0)
What is the CIDR mask for Class A IPv4 addresses?
/8
What is the CIDR mask for Class B IPv4 addresses?
/16
What is the CIDR mask for Class C IPv4 addresses?
/24
What is it called when a router will remap (translate) private addresses to a public IP address as we go on the internet?
Network Address Translation (NAT)
What is the private range for IPv4 class A?
10.0.0.0 - 10.255.255.255
What is the private range for IPv4 class B?
172.16.0.0 - 172.31.255.255
What is the private range for IPv4 class C?
192.168.0.0 - 192.168.255.255
How many bits does IPv6 addressing use?
128 bits
Which of the IP Addressing is represented by hexadecimals? (IPv4 or IPv6?)
IPv6
You specify all the information, like IP address, subnet mask, and more. What way are you getting this IP address? (Static or dynamic)
Static
Information like IP address, subnet mask and more are done for you automatically. What way are you getting this IP address? (Static or dynamic)
dynamic
every time a device connects to a network, it gets assigned an IP address by this
Dynamic Host Configuration Protocol (DHCP)
Device will assign itself an IP address if DHCP is not available; aka as link-local address; can communicate on the local network but not outside of it
APIPA (Automatic Private IP Addressing)
the range of addresses that a DHCP server can offer to client hosts
in a particular subnet
DHCP Scope
What range does APIPA fall under for IPv4 addresses?
169.254.0.0/16 (169.254.0.1 - 169.254.255.254)
What range does APIPA fall under for IPv6 addresses?
fe80::/64
translates domain names to IP addresses
Domain Name System (DNS)
device located at the boundary of a network; manages all of the data that up flows and downflows; transfers communication between local network and the internet; generally the router acts as this
gateway
connection-oriented protocol; must establish a connection; transmits data in both directions; about reliability - because it will guarantee data will be delivered in the right order
Transmission Control Protocol (TCP)
connectionless protocol; data is continuously sent to the recipient whether or not it is actually received; no error checking or confirmation
UDP (User Datagram Protocol)
a process-specific or an application-specific software construct serving as a communication endpoint, which is used by the transport layer protocols of IP protocol suite, such as UDP and TCP
network ports
moves files from one system to another
File transfer protocol (FTP)
Which port does FTP use to transfer data?
TCP 20/21
method used to manage network devices securely at the command level
secure shell (SSH)
Which port does SSH use for communication?
TCP 22
used for management of network devices at the command level but only provides an unsecured connection, and not recommended over public networks
Telnet
Which port does Telnet use for communication?
TCP Port 23
used to transfer mail between mail servers; used when end-user send email to a mail system
Simple Mail Transfer Protocol (SMTP)
Which port does SMTP use for communication?
TCP 25
translates domain names to IP addresses and used on public and private networks
DNS (Domain Name System)
Which port does DNS use for communication?
TCP/UDP 53
used to assign an IP to devices
DHCP
Which port does DHCP use for communication?
UDP 67/68
used to display web pages; data transfer is unsecured/unencrypted
HTTP (hypertext transfer protocol)
Which port does HTTP use for communication?
TCP 80
also used by browsers to display pages; data is encrypted bidirectionally using SSL or TLS
HTTPS (Hypertext Transfer Protocol Secure)
Which port does HTTPS use for communication?
TCP 443
used to retrieve emails from a server
Post Office Protocol (POP) v3
Which port does POPv3 use for communication?
TCP 110
used to retrieve email from a server; supports a wider array of remote mailbox operations
Internet message access protocol (IMAP)
Which port does IMAP use for communication?
TCP 143
method of collecting and organizing information about managed devices such as routers, modems, etc.
Simple Network Management Protocol (SNMP)
Which port does SNMP use for communication?
TCP/UDP 161/162
central protocol used to interconnect Microsoft Windows devices
NetBIOS over TCIP/IP (NetBT)
Which port does NetBT use for communication?
TCP/UDP 137/138/139
mechanism for accessing and maintaining distributed directory information
Lightweight Directory Access Protocol (LDAP)
Which port does LDAP use for communication?
TCP/UDP 389
Windows-compatible file and printer sharing services on a local network (also sometimes referred to as Common Internet File System [CIFS])
Server Message Block (SMB)
Which port does SMB use for communication?
TCP 445
view the remote desktop of a device across the network
Remote Desktop Protocol (RDP)
Which port does RDP use for communication?
TCP 3389
one of the first devices used to connect networks together; aka multiport repeater because it simply transmits any signal going into all data interfaces of the device; only allows communication in one way
Hub
What is the speed that hubs transmit?
10/100Mbits/s
more intelligent than the legacy hardware; forwards traffic to the right interface based on destination; vary in size depending on intended use
switch
forwarding decisions are completed by this
ASIC (application specific integrated circuit)
what is an unmanaged switch?
simply enables devices on a network to communicate
What is a managed switch?
allows more advanced settings such as limiting or turning off ports, adjusting parameters
used to route traffic from one subnet to another; makes forwarding decisions based on destination IP
Router
can connect multiple types of networks together
router
A switch that has a router embedded
Level 3 router
bridge that connects wired and wireless networks; can make smart forwarding decisions
Access Point
converts signal between analog and digital; first used standard phone line; generally have cable modems
Modem (modulator/demodulator)
just like a cable modem but for fiber technology; goal of this is to convert signal from optical to electrical and vice versa; sits between ISP and ethernet devices
Optical Network Terminal (ONT)
hardware responsible for connecting the device to the network
Network Interface Card (NIC)
used for larger networks; endpoint for connecting from a person’s desk to the switch/router for easier management; contains no intelligent circuitry
Patch panel
sends power over an ethernet connection; common for security cameras, VoIP telephones; capability typically found in switch or using an injector
Power over Ethernet (PoE)
What is the IEEE standard for PoE?
802.3af - 12.95 W
What is the IEEE standard for PoE+?
802.3at - 25.5 W
What is the IEEE standard for PoE++?
802.3bt (Type 3) 51 W
What is the IEEE standard for PoE++ Type 4?
802.3bt Type 4 - (71.3 W)
can be software or hardware; on router or dedicated hardware; filters traffic by port number or by application
Firewall
newer approach to managing network hardware; goal is to use software-based controllers & APIs to communicate with the underlying hardware; central place to manage entire network via a single pane of glass
Software-Defined Networking (SDN)
What is a typical order for hardware in a network?
ISP>Modem/ONT>Router>Switch> Access Point>Devices
Network type that covers a very small area
Personal Area Network (PAN)
What network type are personal devices and peripherals like wireless headsets and printers usually on?
PAN
Network type that generally are used in a single site or office building when people need to share resources among themselves, but not with the rest of the outside world
Local area network (LAN)
The same as a LAN but totally wireless
Wireless Local Area Network
Network type that makes it easier for network administrators to partition a switched network to match the functional and security requirements of their systems without having to run new cables or make major changes in their current network infrastructure
Virtual Local Area Network
Network type that consists of a computer network across an entire city, college campus, or small region; usually connects multiple LANs together to form a bigger network
Metropolitan Area Network (MAN)
Network type that covers an area wider than a LAN; generally covers multiple buildings to different countries; the most popular is the Internet
Wide Area Network
Network type that is a dedicated high-speed network that delivers shares pools of storage devices to several servers
Storage Area Network (SAN)
Internet connection type that uses existing phone wires that is asymmetric because the download speed is faster than the upload speed
DSL (Digital Subscriber Lines)
What is the speed that DSL could reach to?
100 Mbps, but average 7 Mbps
Internet connection type that uses through coaxial lines traditionally used for TV
Cable
What is the speed of cable internet?
anywhere between 10 to 300 or 400 Mbps
Internet connection type that uses optic fiber cables that can run internet, voice communication, and TV on the same cable
Fiber
What is the speed of a fiber connection?
1 Gbps, highest 2.5 Gbps
Internet connection type where modem communicates directly to a satellite; mainly used for remote sites
Satellite
Internet connection type that has been made possible by 5G networks
Cellular
What is the speed a cellular internet connection has?
1 Gbps
Internet connection type that are popular in rural regions because they set towers at the highest points in the rural area and connected by fiber to WISP and homes/businesses have receivers that connect to the tower wirelessly
Wireless Internet Service Providers (WISP)
Wi-Fi standard that first came out in 1999; functions on the 5 GHz band, speeds of 54 Mbps, low range
802.11a
What band does 802.11a use?
5 GHz
What is the speed of the 802.11a standard?
54 Mbps
Wi-Fi standard that first came out in 1999, functions on the 2.4 GHz, with a speed of 11 Mbps, better range
802.11b
What is the band that 802.11b functions on?
2.4 GHz
What is the speed of the 802.11b standard?
11 Mbps
Wi-Fi standard that came out in 2003, functions on the 2.4 GHz band at 54 Mbps speed, better range and is fully backwards compatible with 802.11b
802.11g
What band does 802.11g use?
2.4 GHz
What is the speed for the 802.11g standard?
54 Mbps
Wi-Fi standard that came out in 2009, functions on the 2.4 GHz and 5 GHz band at 600 Mbps speed
802.11n
What band does 802.11n standard use?
both 2.4 GHz and 5 GHz
What is the speed of the 802.11n standard?
600 Mbps
multiple antennas on the access points introduced when 802.11n was introduced
Multiple-input Multiple-Output antennas (MIMO)
Wi-Fi standard that came out in 2014, functions on the 5 GHz band at 7 Gbps speed
802.11ac (WiFi 5)
What is the band that 802.11ac (WiFi 5) uses?
5 GHz
What is the speed of the 802.11ac (WiFi 5) standard?
7 Gbps
Wi-Fi standard that came out in 2019, functions on both 2.4 GHz band and 5 GHz at 14 Gbps speed
802.11ax (WiFi 6)
What is the speed of 802.11ax (WiFi 6) standard?
14 Gbps
What band does the 802.11ax (WiFi 6) standard use?
both 2.4 GHz and 5 GHz
Wi-Fi standard that came out in 2021, functions on the 6 GHz band
802.11ax-2021 (WiFi 6E)
What band does the 802.11ax-2021 standard function on?
6 GHz
Type of frequency where a company needs to buy the right to transmit at a certain frequency; greater reliability
Licensed
Type of frequency where everyone can use this frequency to transmit data
Unlicensed
What type of frequency does WiFi use?
Unlicensed
What are the actual frequencies we talk about when discussing the 2.4 GHz frequency?
2.4-2.5 GHz
What are the actual frequencies we talk about when discussing the 5 GHz frequency?
5.1-5.8 GHz
In 2020, this frequency was opened to unlicensed use, but previously it was called the safety band and was used for transportation-related communication
5.9 GHz
How many channels does the 2.4GHz frequency have?
14 channels, while only 11 are used in the US
How big is the range for the 2.4 GHz channel?
20-22 MHz
How much MHz separate each channel in the 2.4GHz frequency?
16-22 MHz
Which are the only channels in the 2.4 GHz that don’t overlap?
1, 6, and 11
How many channels does the 5GHz frequency have?
24 x 20 MHz non-overlapping channels
What does it mean to have a wider channel in a frequency?
Created by bonding; able to have more data passthrough - more data can be pushed through it
Wireless standard for exchanging data over short distances (in theory, distances of up to 800 ft) and has very low battery consumption, but has a lower speed
Bluetooth
What band/frequency does Bluetooth operate on?
2.4GHz
What is the speed of Bluetooth?
1-3 Mbps
Wireless standard that enables low range communication between compatible devices, usually under 10 cm
Near Field Communication (NFC)
Wireless standard; technology where can have digital data encoded in RFID tags that are captured by a reader via radio waves; similar purpose as a bar code; does not need direct line of sight
RFID (radio frequency identification)
Network server whose goal is to deliver web-based content; can be public or private
web server
Network server whose goal is to create a central location to store documents and files
File server
Network server whose role is to manage and distribute print jobs; allows users to print across multiple printers in the enterprise
Print server
Network server whose role is to manage email services within the organization, whether inbound or outbound and accessing email
Mail server
Network server whose goal is to consolidate logs from multiple sources in a single location
Syslog Server
Network server whose role is to handle user authentication and permissions; 1) are you who you say you are? 2) checking whether user has permission to access a resource. 3) Auditing, logging information
Authorization, Authentication, and Accounting (AAA) server
Network server whose goal is to translate fully qualified domain names into IP addresses
DNS Server
Network server whose goal is to deliver IP addressing to clients using DHCP; ensures there are no duplicate IP addresses in the network
DHCP server
Internet appliance whose goal is to distribute traffic across multiple resources; can provide fault tolerance
Load balancer
Internet appliance whose goal is to handle all external requests by users on a network; can provide different levels of security, privacy, and functionality
Proxy server
Internet appliance whose goal is to check every email and block spam before it reaches the e-mail server; often includes antivirus capabilities
Spam gateway
Internet appliance whose goal is to provide a single appliance that combines multiple security features in a single hardware appliance
Unified Threat Management (UTM)
System that has a combination of hardware and designed to perform a dedicated function
Embedded system
Embedded system used on large scale industrial devices; designed to be easily operated and repaired; doesn’t have much security
SCADA (Supervisory Control and Data Acquisition System)
Network host that involves extending internet connectivity to traditionally non-internet enabled devices
Internet of Things (IoT)
Network troubleshooting tool that allows you to cut ethernet cables to the required length; presser to connect on the cable jacket (RJ 45 connector)
Crimper
Network troubleshooting tool used to remove the protective coating of a wire
Cable stripper (wire stripper)
Network troubleshooting tool used to find two ends of a cable
Tone Generator and Probe
Network Troubleshooting Tool that validates networking cables are well connected; can help with interference and signal loss measurements
Cable tester
Network troubleshooting tool that is useful when need to troubleshoot a physical interface; sends back everything that was sent through it
Loopback plug
Network troubleshooting tool used with patch panels or punchdown blocks; physically connect wire to connectors on a punchdown block; cuts down wire to correct size
Punchdown tool
Network troubleshooting tool that connects directly to cabling infrastructure to split or copy packets for analysis, security or general network management
Network Tap (Test access point/Terminal access point)
Network troubleshooting tool that are either hardware or software that shows signal strength or if have interference; allows for network optimization as well as troubleshooting
Wi-Fi Analyzer
allows you to set different priority on network traffic based on MAC address, IP address, port number, application
Quality of Service (QoS)
DNS Record which is an IPv4 address record that maps a name to an address
A record
DNS Record which is an IPv6 address record that maps a name to an address
AAAA record
DNS Record that directs mail to a mail server; will not point to an IP directly but to a full domain name, then will use A/AAAA record to find the actual IP of the server; can have different of these records with different priorities
MX (Mail Exchanger) Records
DNS Record originally intended for human-readable notes; today used for many purposes today like domain ownership verification; can save information related to spam prevention
TXT
How can TXT records on DNS help protect from spam?
It helps email servers determine if a message is truly from a trusted domain
Spam Management TXT record which lists all the servers that are authorized to send email messages from a domain
SPF Record
Spam Management TXT record which works by digitally signing each email using a public-private key pair; the public key is hosted in a TXT record associated with the domain
DKIM
Spam Management TXT record that is a framework that aligns SPF and DKIM to authenticate emails and tell email servers what to do with emails that are trying to spoof domain
DMARC
Network type that is used in industrial applications; replaces bulky wiring systems, reducing weight and cost
CAN (controller area network)
A switch that allows a user to connect a single keyboard, video display device and mouse to multiple computers
KVM switch
What is the maximum data transmission speed for Bluetooth technology?
3 Mbps
