Network+ Fundamentals Flashcards
GSM
Global System for Mobile Communications was a standard that used multiplexing for 2G
CDMA
Code Division Multiple Access used a code instead of multiplexing for 2G
Latency
PING. A delay between the request and the response (waiting time)
Jitter
measures the variability of the delay, it’s the time between frames
SNMP
Simple Network Management Protocol is used to remotely monitor and manage network devices connected over an IP. SNMP v3 is currently the standard
MIB
Management Information Base or a database of data
OIDs
Object Identifiers are addresses used to uniquely identify managed devices and their statuses
MTTR / MTBF
They are both KPI key performance indicators usd to assess the reliability and maintenance effciency of systems and componets.
Mean time to restore or repair and the Mean time between failures
bonus (SLA) Service level agreement
SIEM
Security Information and Event Management collects log and event data for organizations or auditing and security purposes.
NMAP
A network mapper that finds and learns more about network devices, notably through port scanning. Example. It can identify what OS a device may be using without logging in or authenticating. It also provides additional scripts.
Vulnerability Scanner
unlike penetration testing, this is minimally invasive. Good at finding unknown devices on a network. Test from outside and inside. Identify the lack of security controls like firewall or anti-virus.
Protocol analyzers
solve complex application issues frame by frame. It can capture data from your ethernet connection or a wireless network. View unknown traffic patterns.
FTPS
(Port 21, 990) File Transfer Protocol over SSL (FTP-SSL)
SFTP
FTP using SSH which provides file system functionality
SSH
(Port 22) Secure Shell which is more focused on secure remote access and command execution
SSL
(Port 443) Secure Socket Layer makes sure that all data is encrypted from servers to web browsers. Similar to TLS
TFTP
Trivial File Transfer Protocol which is used for configuring VoIP phones.
WPA
Wifi Protected Access it replaced WEP (Wired Equivalent Privacy)
TKIP
Temporal Key Integrity Protocol is an encryption algorithm to secure a wireless network. 64 bit integrity check and prevents replay attacks.
RC4
stream cipher used with WPA
A stream cipher is a method of encryption where plaintext digits are combined with a pseudorandom cipher digit stream
WPA2
uses AES (Advanced Encryption Standard which replaced RC4 and uses CCMP which replaced TKIP
CCMP
It’s an encryption protocol used in wireless networking for security. It encrypts and authenticates.
Counter Mode with Cipher Block Chaining Message Authentication Code Protocol uses AES for data confidentiality. Uses a 128-bit key and a 128-bit block size. Offers also authentication and access control
EAP
Extensible Authentication Protocol which is an authentication framework. Many different ways to authenticate based on RFC standards. WPA and WPA2 use five EAP types as authentication mechanisms
EAP-TLS
Extensible Authentication Protocol Transport Layer Security. TLS was originally used for web servers but is now being used for wireless authentication. It’s purpose is to authenticate network access.
EAP-TTLS
EAP Tunneled TLS which supports other authentication protocols in a TLS tunnel.
PEAP
Protected EAP encapsulates EAP in a TLS tunnel
MAC Filtering
can be perform on a wired and wireless network. It’s a security measure used to control access to the network. Every NIC has a identifier (MAC address). Mac filtering involves setting up a list of allowed MAC addresses on a network device, such as a router or access point, to permit or deny network access to devices based on their MAC addy.
Geofencing
is a location-based service in which an app or other software uses GPS, RFID, Wi-Fi, or cellular data to trigger a pre-programmed action when a mobile device or RFID tag enters or exits a virtual boundary set up around a geographical location, known as a geofence.
Denial of service
criminals make a service from available to unavailable. This is why it’s import to PATCH. Sometimes not intended.
Network DoS
a layer 2 loop without STP
Bandwidth DoS
downloading multi-gigabyte Linux distributions over a DSL line would be a good example
DDoS
Distributed Denial of Service
- Launch an army of computers to bring down a service. Attacks on multiple fronts. Asymmetric threat. The attacker may have fewer resources than the victim.
DDoS amplification
Turn your small attack into a big attack which is becoming increasingly common. Uses protocol with little (if any) authentication or checks like NTP, DNS, or ICMP
ICMP
(Layer 3) Internet Control Message Protocol is used for sending error messages and operational information regarding the status of IP operations.
Logic Bomb
waits for a predefined event often left by someone with a grudge.
- Time bomb: waiting for a date and time
- User bomb: something a user does like waiting for a backup process to occur
- Difficult to identify
Wardriving
Combine WiFi monitoring and a GPS which gives you a huge amount of intel in a short period of time. A lot of intel in a short amount of time.
Phishing
tricking individuals by revealing sensitive information by disguising malware as a real site or email.
Spear Phishing
phishing with insider information which can result in making the phishing a lot more believable
Ransomware
Someone wants your money. They’ll take your computer in the meantime. Often may be fake ransomware. Meaning they don’t have your data.
Crypto-malware
your data is unavailable until you provide cash. The malware encrypts your data files and you must pay the bad guys to obtain the decryption key.
DNS Poisoning
(DNS spoofing or DNS cache poisoning) Modify the DNS server. You can do this by modifying the client host file.
DNS spoofing invokes the attacker intercepting and altering DNS queries to provide false responses. Goal is to redirect users to fraudulent websites that mimic legitimate ones to either phish or distribute malware.
DNS Cache Poisoning is a type of spoofing that targets the DNS servers themselves rather than individual users. Inserts a false address record into the DNS server’s cache.
VLAN hopping
the act of hopping from one VLAN to another. You do this by using methods such as switch spoofing or double tagging.
Switch spoofing
It’s a network attack where an attacker configures a device to mimic a switch’s behavior in order to manipulate or bypass network security.
some switches support automatic configuration which has no authentication required. In other words, you can pretend to be a switch. Send trunk negotiation. Admins should disable trunk negotiation
Double tagging
craft a packet that includes two VLAN tags. The first native VLAN tag is removed by the first switch (per usual) and the second “fake” tag is now visible to the second switch. This is a one-way trip, but can be used as DoS.
FIM
File Integrity Monitoring is a security process and technology that involves continuously monitoring and validating the integrity of files and file systems to make sure they haven’t been violated by things like malware.
SFC
System File Checker (Windows)
for Linux it’s tripwire
Flood guard
configure a maximum number of source MAC addresses on an interface. The switch monitors the number of unique MAC addresses. Once you exceed the maximum port security activates.
DHCP snooping
IP tracking on a layer 2 device (switch)
- the switch is a DHCP firewall
- switch watches for DHCP conversations
- Filters invalid I{ and DHCP information
DMZ
demilitarized zone which is an additional layer of security between the internet and you
Cable crimpers
“pinch” the connector onto a wire and connect the modular connector to the Ethernet cable. Metal prongs are pushed through the insulation.
Crimping best-practices
get a good crimper
good pair of electrician’s scissors\cable snips
get a good wire stripper.
Make sure you are using the correct modular connectors
Cable testers
helps you identify if the crimps are working. Doing a continuity test to see if everything is working properly. NOT used for frequency testing.
TDR and OTDR
Time Domain Reflectometer / Optical Time Domain Reflectometer which both estimate cable lengths and identify splice locations and cable impedance. Use it commonly when first installing cable infrastructure.
Tone generator
puts an analog sound on the wire. Inductive probe which means it doesn’t need to touch the copper and you can hear the tone through a small speaker
Helps with cable identification and tracing cable routes
Loopback plugs
if you’re trying to perform troubling shooting on a network connection. It can perform some tests sending some signals to know what kind of signals it’s receiving
Spectrum analyzer
examine all the different frequencies and be able to tell where the frequencies are. If you connecting a WAP for the first time and want to know if there is any interference that is being caused in the area
WAP is a wireless application protocol
Multimeters
tools that allow you to test AC and DC voltage. Also continuity tests to see if you’re getting connections from one end of a cable to another
traceroute
helps you determine the route a packet takes to a destination. Uses ICMP TTL
Internet Control Message Protocol used for error reporting
nslookup
lookup information from DNS servers, for Windows
dig
Domain Information Groper lookup information from DNS servers more advanced than nslookup
ipconfig/ifconfig
Helps determine an IP address. commands for Windows and Linux respectively. MOST of my troubleshooting starts with my IP address. Determines TCP/IP and network adapter information with some additional IP details.
netstat
is a command-line tool that displays network connections (both incoming and outgoing), routing tables, and a number of network interface statistics.
Routing table is a data table stored in a network router or a host that lists the routes to particular network destinations.
IP address
Subnet mawk
Next Hop
Interface/Port
Metric (distance to reach destination)
Route source. (How a route was learned)
Network statistics
netstat -a
- show all active connections
netstat -b
- show binaries (Windows)
netstat -n
- do not resolve names
iptables
in Linux helps you configure firewalls. Provides stateful firewall.
tcpdump
capture packets from the command line and apply filters, view in real-time. You can also save the date and use it in another application
pathping
combine ping and traceroute. The first phase runs a traceroute. The second phase measures round trip time and packet loss at each hop.
route
shows where traffic is routed.
Address Resolution Protocol
ARP determines a MAC address based on an IP address
arp -a
- view local ARP table
POP3
(Port 110) Post Office Protocol -3 is used for receiving email from a mail server from a local email client. Enables users to access their emails offline.
What makes up an IP address
network ID, subnet mask, host ID
10.0.0.0/8
according to RFC 1918, this address space is defined for large internet networks. These are private and non-Internet routable addresses
orchestration software
deals with the automated deployment, scalability, configuration management, service discovery, load balancing, and health monitoring and recovery. Large part deals with the cloud
maximum theoretical speed of Dial-up with the V.92 specification
V.92 is a standard for modems that was introduced in 2000.
56kb/second
wireless client density
important for designing WLAN infrastructure. It refers to the number of wireless devices connected to a particular wireless network
CSU/DSU
Channel Service Unit/Data Service Unit helps with connecting LANs to WANs
domain’s zone file
it maps domain names to IP addresses
MTRJ
Mechanical Transfer Registered Jack is a type of fiber optic connector which offers a compact design and a method for duplex connectivity. It resembles an RJ-45 connector and allows greater port density.
LDAPS
(TCP Port 636) Lightweight Directory Access Protocol uses SSL.
LDAP
(TCP Port 389) Lightweight Directory Access Protocol that can search a directory service for objects. Microsoft Active Directory (AD) is an example of a directory service that uses LDAP to locate objects.
static IP address
this is a fixed, unchanging IP address assigned to a computing device. It’s simple, reliable, and sometimes a requirement for certain applications. Especially for hosting servers, that way people can go on the website. GREAT for routers, printers, and servers.
1000BaseLX standard
Part of the IEEE 802.3z set of Gigabit Ethernet standards. It specifies a Gigabit Ethernet implementation using long-wavelength (LX) laser transmission over fiber optic cables. 1Gbps and can operate both single and multi-mode. It utilizes a 1300 nm laser over 9-micron single-mode fiber and can reach distances up to 10 kilometers.
LX (Long-wavelength) uses single-mode fiber and up to 550m
NTP
(UDP Port 123) is used both for request and reply of NTP packets; a symmetrical port
Network Time Protocol
RG-59 vs RG-6
RG-59 and RG-6 are both coaxial cables
RG-6 - has a larger conductor which supports higher frequency and bandwidth. Lower signal loss and are usually thicker than its counterpart.
NAS
Network attached storage is a dedicated file storage device that provides multiple users and client devices with access to data over a network
SMBs
Server Message Blocks is a protocol used by NAS to enable users on a network to access files, printers, and other shared resources. It’s good because it offers data protection and redundancy, scalability, and it’s cost effective. Responsible for performing commands against a file structure
NAS is network attach storage
40GBaseT standard
40Gbps and a max distance of 30 meters. It was made through the IEEE 802.3bq task force
DHCPv6
It can use of Stateless Address Autoconfiguration (SLAAC) for IP address assignment with DHCPv6 for the distribution of additional network configuration parameters. A router sends RA messages with specific flags to set to indicate how devices should obtain their IP addresses.
Stateful DHCPv6 assigns IPv6 addresses to devices and maintains a record (state) of each assignment, similar to DHCP in IPv4
Stateless does not assign IP addresses because it can generate their own from SLAAC
RA is Router Advertisement
RA
Router Advertisement is a protocol used in IPv6 and part of the NDP. They are sent out by routers to advertise their presence
commands
M flag (managed address configuration) when the flag is set to 1 it shows that addresses are available
O flag (other configuration) When set to 1, this flag tells the hosts that other configuration information, excluding IPv6 addresses, is available via DHCPv6. This typically means that a device should use Stateless Address Autoconfiguration (SLAAC) for its address configuration and DHCPv6 for other settings, like DNS server addresses.
H.323 protocol
Was among the first protocols established for VoIP and multimedia communications over IP.
100BaseSX standard
Like 100BaseFX, 100BaseSX also uses fiber optic cables but is optimized for shorter distances.100 Mbps and supports up to 100m in length. 100BaseSX can be seen as a solution for organizations looking for a cost-effective, high-speed fiber optic LAN technology for relatively short distances.
SIP
(Port 5060 UDP and TCP not encrypted and Port 5061 is TCP and encrypted)
Session Initiation Protocol is a signaling protocol used for initiating, maintaining, managing, and terminating real-time sessions that involve video, voice, messaging, and other communications applications and services between two or more participants over an internet protocol (IP) network.
E3 connection
An E3 connection, part of the PDH (Plesiochronous Digital Hierarchy) system used primarily in Europe, provides a total bandwidth of 34.368 Mbps (megabits per second).
1000BaseSX
1000BaseSX, a standard for Gigabit Ethernet over fiber-optic cabling, is designed for short-range communication over multimode fiber. When using 50-micron multimode fiber-optic cabling, which offers better performance than the older 62.5-micron multimode fiber, 1000BaseSX can achieve distances up to 550 meters.
CNAME
It’s a type of resource record in the DNS. Canonical Name record helps with Alias Management: CNAME records are ideal for when you need to alias one domain name to another. It allows an FQDN to resolve to an A record
Allows for different names under one name for a website lookup.
FQDN
Fully Qualified Domain Name is composed of a host name and a domain name. It includes all domain levels, from the top-level domain (TLD) to the specific subdomain or hostname, and it’s used to uniquely identify a specific server or service on the internet or a private network.
A Record
It’s a DNS record, Address record which is used to map a domain named to an IPv4 address
Links a domain like ‘example.com’ to an address like ‘192.0.2.1’
What is the function of a fiber-optic transceiver in the network equipment?
It converts between the internal electrical signaling and light.
Forward zone
are used in DNS to map domain names to IP addresses. This is the most common use of DNS, allowing users to access websites and other resources on the internet by using human-readable names instead of numerical IP addresses.
It’s a file or data base entry that contains mappings from domain mail to IP addresses
A forward zone HAS an A record inside. A forward zone contains records of FQDNs. CNAMEs are also in a forward zone.
Reverse zone
are used to map IP addresses back to domain names. This process is known as reverse DNS lookup or reverse resolution and is the opposite of the forward lookup process.
host files
originally used for translation of hosts to IP addresses. When going on a website, a computer will first check its host files to see if there is a proper ip address for the domain listed if not then it will then look to an outside DNS
CNA
Converged Network Adapter allows servers to communicate over Ethernet networks while providing support for Fiber Channel storage protocols, essentially bridging the gap between traditional Fiber Channel (FC) storage networks and Ethernet-based local area networks (LANs). It acts as an Ethernet card and encapsulates FC commands into Ethernet frames.
Secondary DNS Server
its use is to act as a backup for the primary DNS Server.
FQDN dot
at the end of a domain if you put a period (.) at the very end it signals that you want this exact domain and to not look elsewhere
pull method
is a model where individual client machines or servers fetch (or updates, configurations, and instructions from a central repository or management server at regular intervals or based on certain conditions. Primarily ushes a push method
Ansible
It was created as a replacement for Chef and Puppet and allows for a hybrid approach to orchestration.
DSLAM
its primary function is to connect multiple customer DSL connections to a high-speed backbone network. The DSL Access Multiplexer (DSLAM) is a piece of equipment located at the central office, or telephone provider’s main location. It is an integral part of the DSL network and faciliates communication between the central office and the modem at the customer’s location.
DHCP order for a handshake
DORA Discover, Offer, Request, Acknowledge
Punchdown blocks
are a type of electrical connection used in telecommunication and network wiring. They are almost always used with analog or digital time division multiplexing (TDM) phone installations.
SOA
Start of authority indicates the start of a zone of authority and provides essential details about the zone. The Start of Authority (SOA) record in a DNS zone is primarily responsible for keeping records up-to-date on the secondary servers. It includes a serial number and a refresh parameter, which tells the secondary DNS servers how often to request a refresh of the SOA records.
APNIC
Asia Pacific Network Information Center manages public IPv4 addresses
colocation
Colocation (or “colo”) is a data center facility service where businesses can rent space for servers and other computing hardware
SDSL
Symmetrical Digital Subscriber Line uses DSL technology over existing copper lines. SDLS and T1 leased lines deliver the same speed.
DOCSIS
Data Over Cable Service Interface Specification is a telecommunications standard that allows for the addition of high-speed data transfer to an existing cable TV (CATV) system.
SQLnet
also known as Oracle Net enables communication between Oracle databases for exchanging information for queries.
ISDN
It’s a telecommunication technology that enables the digital transmission of voice, video, data, etc.. over the PSTN public switch telephone network
Integrated Services Digital Network is typically implemented in two modes, Basic Rate Interface (BRI) and Primary Rate Interface (PRI)
F-connector
primarily used for cable TV and cable modem connections.
Spine-Leaf network
framework for database networks for high speed and low latency.
Spine Switch: layer consists of high-capacity switches arranged in a mesh or Clos topology. These spine switches form the core of the network and serve as the backbone for connecting all the leaf switches.
Leaf Switch: consists of access switches that connect directly to servers, storage devices, and other network endpoints. Each leaf switch is typically connected to every spine switch, forming a full mesh topology between the leaf and spine layers.
Unicast
is a one-to-one conversations between two devices in a network, where the destination MAC address at the Data Link layer is a specific MAC address on the network.
PAT
Port Address Translation is to allow multiple devices within a private network to share a single public IP address for outgoing internet connections. PAT is a type of Network Address Translation (NAT) technique commonly used in IPv4 networks.
vNIC
Virtual network interface card is a software that behaves or pretends to be a physical hardware. It enables direct communication between the VM and the virtual switch.
iSCSI
(Internet Small Computer System Interface) can range from 1Gbps to 40Gbps. It is a protocol used for transporting SCSI commands over TCP/IP networks.
WWN
Fiber Channel Worldwide Names are likened to MAC address.
World Wide Name is a unique identifier used in storage networking.
10GBaseT
IEEE 802.3an, Ethernet speed for 10Gbps, uses TIA/EIA Category 6 or higher cable. Has a maximum distance of 55m is Cat 6
Cat6a is 100 meters
DHCP Reservation
The client’s MAC address is tied to a specific IP address. When a DHCP reservation is made for a client on a DHCP server, the client’s MAC address is linked to a specific IP address, ensuring that the client always obtains the same IP address when the DHCP Discovery packet is received by the server.
SMTP
Simple Mail Transfer Protocol is invoked in sending and relaying emails, downloading them from the server to client. It operates in the process of delivering the email and not in client access on the email server.
Relay means where an email server forwards an email from one domain to another on behalf of a sender.
POP3 receives emails
10BaseT
defined by the IEEE as 802.3i and uses cat 3,4 or 5
10Mbps
1000BaseT
has a maximum distance of 100 meters.
InfiniBand
high speed networking technology used in data centers. InfiniBand is primarily used for high-performance computing (HPC) and cluster connections. Very few companies produce the high-end switching equipment needed for InfiniBand.
Fibre Channel
high speed networking technology used in data centers. Fibre Channel is traditionally used for connecting servers to shared storage devices and for storage area networks (SANs)
Cat 7 and Cat7a
both can go up to speeds at 10Gbps. However, Cat 7a is tested at a higher frequency of 1000MHz
three-tiered networking model
Access Layer, Distribution Layer, and the Core Layer.
Router Solicitation
RS requests operate on IPv6 networks. Its procedure is to solicit a Router Advertisement (RA) from the network routers.
It’s part of the Neighbor Discovery Protocol (NDP)
Class D
Class D network IDs are specialized IP addresses for multicasting, as defined by the IETF and RFC5735. They are not used for individual network.
Multicasting is when data is sent to multiple destinations in a single transmission.
BIX punch block panel
Building Industry cross connect predominantly found in Nortel phone switch installations. The wires from the Nortel switch are punched on the back of the BIX punch block panel, and the front is used for cross-connecting a 110 or 66 block that leads to the phone extension.
What is the main difference between the Three-tiered networking model and the Collapsed-core model?
Three-tiered model is more complex but allows for greater scalability and is better suited for large, distributed networks.
Collapsed-core model is simplifying the network structure which can be advantageous for smaller networks.
Collapsed core has an Access Layer and a collapsed core/distribution layer
Anycast address
are used for a one-to-nearest connectivity. The address is a standard global unicast address, but it is populated in multiple routing tables. This means that a network packet sent to an anycast address will be delivered to the closest interface (usually determined by the routing protocol metrics).
FTP active and passive mode
The active and passive modes in FTP mainly differ in who initiates the transfer. In active mode, the server initiates the transfer by sending information from TCP port 20 on the server to the client.
In passive mode, to address firewall and NAT network issues, the client initiates the transfer from a port above TCP 1023 and sends it to a waiting port on the server above TCP 1023. The client initiating the transmission to the server is what firewalled and NAT networks expect as a dataflow.
classless IP subnetting
The text states that the classless IP address category allows for subnetting and supernetting and does not adhere to the classful assignment of the IETF due to the scarcity of IPv4 addresses.
BNC
Bayonet-Neilll-Concelman OR British Naval Connector is a type of RF (radio frequency) connector used for coaxial cable for networks and security camera systems.
- Uses 10Base2 LAN
TFTP
provides no security and is simplistic in operation. It is often used to both boot computers over the network via the Preboot Execution Environment (PXE) and transfer software images for network devices during updates. Network devices also use TFTP to back up and restore configurations.
Northbound Interface and SDN
NBI in a software-defined network connects the application layer to the control layer, specifically allowing applications and APIs access to monitor and manage the network devices that are under (or south of) the controller. It facilitates the interaction between applications/APIs and the control layer
Virtual firewall kernel module
is a software module that integrates directly into the kernel of an operating system. It operates at a low level. intercepting and filtering network traffic as it enters or leaves the host system or traverses between VMs on the same host. NOTE this module applies policies to all hosts in the cluster. When a kernel module is used, the traffic never leaves the host, unlike in the case of a virtual firewall appliance.
Virtual firewall appliance
this is a complete firewall solution packaged as a virtual machine. This includes both the firewall software and the underlying operating system all encapsulated within a VM container.
What is the main function of a Channel Service Unit/Data Service Unit (CSU/DSU) in a T1 service?
The Channel Service Unit/Data Service Unit (CSU/DSU) is primarily used to convert the channels back into a stream of data. It takes the data from each of the 24 channels or ’buckets’ and combines it into a consistent, usable data stream.
QoS
quality of service is a networking concept and set of technologies used to manage network traffic. Some key functions include traffic prioritization, bandwidth management, congestion management, and traffic shaping.
Power over Ethernet
this is a technology that allows electrical power to be passed along with data over standard twisted-pair Ethernet cabling (such as Cat5e, Cat6, etc.) in a network. This enables a single cable to provide both data connection and electrical power to devices, simplifying the cabling and eliminating the need for separate power sources for each device.
demarcation point
the physical point at which the public network of a telecommunications service provider ends and the private network of a subscriber begins
NIC
Network Interphase Card is a hardware component that connects a computer or other devices to a network. It serves as the interface between the device and the network. There are wire and wireless NICS. It’s purpose to provide network connectivity to a device, converting digital data into signals.
Every NIC has an assigned MAC address
Access Layer
Role: The access layer is where devices (such as computers, printers, and other end-user devices) connect to the network. It provides a point of access to the network for these devices and can include features like port security, VLAN segmentation, and power over Ethernet (PoE) for devices that require it.
Functionality: This layer is responsible for controlling which devices are allowed to communicate on the network, managing how devices connect to the network, and implementing policies for network access. Switches at the access layer often provide connectivity to end devices in an office or building.
Distribution Layer
2nd part of the three-tiered networking model.
Role: The distribution layer serves as the intermediary between the access layer and the core layer. It aggregates the data received from multiple access switches before it is transmitted to the core layer for routing to its final destination. It’s also where routing, filtering, and WAN access occur.
Functionality: Key functions include routing, filtering, and implementing policies. The distribution layer can enforce quality of service (QoS) policies, execute access control lists (ACLs), and handle VLAN routing. It acts as a control boundary between the access layer and the core, providing connectivity to services for access layer devices and managing traffic flows.
Core Layer
part 3 of the three-tiered networking model.
Role: The core layer is the backbone of the network, providing high-speed, reliable transportation of data across various parts of the network. In large networks, the core layer connects multiple buildings or sites.
Functionality: The primary functions of the core layer include ensuring efficient and fast data transport across the network and interconnecting the various parts of the network infrastructure. The core is designed for high reliability, availability, and redundancy to minimize downtime and provide fast data transmission.
GIADDR
Gateway Interface Address is part of the DHCP message structure. This field is used by DHCP Relay Agents when forwarding requests from DHCP clients to DHCP servers that are not on the same local network (subnet) as the clients.
IMAP
(Port 143, or Port 993 if used forever SSL/TLS Internet Message Access Protocol allows for multiple email clients to access the same email box simultaneously.
VPN disadvantages
this method does not guarantee a certain level of quality of service end to end. Therefore, applications that are sensitive to latency might run poorly over a VPN.
WiMAX
Worldwide Interoperability for Microwave Access is a wireless communication standard designed to provide high-speed broadband access over long distances. It is specified in the IEEE standard 802.16 to operate on 2 GHz to 11 GHz and another range from 10 GHz to 66 GHz.
SDN
It’s an approach to networking that allows network admins to manage network services by separating the network’s control logic or the control plane from the underlying routers and switches that forward network traffic.
Software-Defined Networking is a concept to networking that uses software-based controllers or application programming interfaces (APIS) to direct traffic on the network and communicate with the underlying hardware infrastructure. Doesn’t use routers and switches, SDN decouples the network control plane from the data plane, allowing for more flexible network management and configuration.
SBI
Southbound Interface is used for communication between the SDN Controller and the network devices (such as switches and routers). Here the SDN Controller can program the data plane to modify how traffic flows through the network.
Data plane is the part of the network that actually forwards the traffic
NBI
Northbound Interface in SDN is used for communication between the SDN Controller and the application and business logic layers that sit above the controller. NBI enables the development of network-aware applications, allowing for more dynamic and automated network configurations and services.
NTP Stratums
Network Time Protocol
Stratum 1: servers are directly connected to an authoritative time source and serve as primary time servers.
Stratum 2: servers receive their time from stratum 1 servers, acting as intermediaries that help scale the distribution of accurate time.
Stratum 16: is used to indicate that a server is unsynchronized and should not be used for time synchronization within the network.
What are the three basic forms of communication a network application can use at the Session Layer?
In Half-duplex comm, both devices can send and receive information but not simultaneously.
Simplex is a one-way or unidirectional flow of information. A Keyboard connected to a computer.
Full-duplex communication allows both divides to send and receive information simultaneously. There’s no need to switch modes, and connection flows freely in both directions.
NIST
National Institution of Standards and Technology promotes U.S. innovation and industrial competitiveness. Leading standards in technology
What does the ’Measured Service’ characteristic of cloud computing as defined by NIST entail?
It involves the monitoring, reporting, and control of resource usage, often serving as a basis for charges.
HBA
A Host Bus Adapter is a hardware device, typically in the form of an expansion card, that allows a computer (the host) to connect to various networking and storage systems.
link-local addresses
these are addresses that are used for local access on a network are unrouteable
H.323 Protocol
The H.323 protocol functionalities as outlined in the text include terminal control (provides endpoint signaling such as the VoIP phone), gateway services (provide transcoding functionality as well as communications with circuit-switched and packet-switched networks), gatekeeper services (provide admission control, bandwidth control, and management of endpoints known as zone management) and multipoint control unit (provides conference call capabilities and call control of data, voice, and video for future in-call conferencing).
APC and UPC
Angled Physical Contact and Ultra Physical Contact are both types of fiber optic connector polishes, commonly used to finish the faces of fiber optic connectors.
UPC cable ends are polished in a domed shape to focus light directly into the center of the fiber core.
APC connectors have an 8-degree angled polish which prevents light that reflects from the far end face from traveling back up the fiber.
Dynamic NAT vs Static NAT
Dynamic Network Address Translation and Static are both methods used to translate private IP addresses into public IP addresses and vice versa.
Static: One-to-One Mapping, Consistent, and resource intensive
Dynamic NAT uses a pool of public address for translations. Private IP addresses are translated to an available public IP address from the pool when they need to access the internet.
POP3
(Port 110) Post Office Protocol allows email clients to log in and retrieve email and listens for request with TCP
If used over an SSL/TLS connection it’s port 995
PTR
Pointer Record is a type of DNS record that provides the reverse mapping of an IP addresses to a domain name. They associate an IP address with a canonical hostname (CNAME). This process is known as reverse DNS lookup.
ARIN
American Registry for Internet Numbers is a nonprofit organization responsible for managing the allocation and registration of Internet number resources within North America and parts of the Caribbean and Atlantic Ocean regions.
Authentication Header
offers connectionless integrity and data origin authentication for IP packets. AH authenticates the entire packet, not just the ESP data and ESP tail.
Features include Anti-Replay Protection, IP Header Protection, Compatibility with NAT, and Operational Modes.
EVC
Ethernet Virtual Connections services multiplexing, granular bandwidth allocation, traffic segmentation and isolation, QoS, interoperability and Standarization. USES LAYER 2
crossover cables
type of Ethernet cable used to connect two similar devices directly to each other without the need for a hub, switch, or router in between. switches to switches, routers to routers, computer to computers, and etc.
Puppet
A configuration management tool that allows system admins and IT pros to automate the provisioning, configuration, and management of a computer system and software infrastructure.
uses XML-RPC protocol over HTTPS to periodically poll the master server.
DHCP options
are parameters that a DHCP server can provide to DHCP clients in addition to the basic information of IP addresses assignment. The router option in DHCP options is considered the most important because it configures a default gateway IP address on the client computer.
VDSL
Very-high-bit-rate Digital Subscriber Line, is a telecommunications technology that provides high speed internet access over copper telephone lines. It can supply asymmetrical speeds of 300Mbps download and 100Mbps upload.
Rapid Elasticity
defined by the National Institute of Standards and Technology (NIST) computer capabilities can be provisioned and released based on the customer’s requirements
Toredo tunneling
is used when an IPv6 host is behind a network address translation, The IPv6 packets are sent as UDP/3544 IPv4 packets to a Toredo server that is connected to the IPv6 network. A Toredo relay is a router that interacts with a Toredo server to facilitate IPv4 clients to IPv6 hosts.
ICMP in IPv6
In IPv6, ICMP plays a larger role than in IPv4. It is responsible for the Neighbor Discovery Protocol (NDP), equivalent to the Address Resolution Protocol (ARP) in IPv4.
QSFP+
The quad small form-factor pluggable+ (QSFP+) transceiver allows for 4×10 Gbps and 4×25 Gbps operation. To fully utilize its quad transceiver, the operation rate would be 40 Gbps and 100 Gbps respectively.
SBI
The Southbound Interface (SBI) in an SDN setup is primarily responsible for communication between the network controller and network hardware devices. It is used to program those devices and ensure they adhere to policies across the network.
NFV
Network Functions Virtualization is a network architecture concept that virtualizes entire classes of network node functions into building blocks that can be linked together to create communication services.
While physical device failures are no longer a concern, the reliability and performance of the host that runs the virtual network functions becomes a critical concern.
VIP
Virtual IP is an IP addrewss that does not correspond to a NIC on a single machine. It abstracts many devices and puts them under 1 IP address.
Which two protocols are used for creating highly available default gateways using a Virtual IP (VIP) and virtual MAC address?
Virtual Router Redundancy Protocol (VRRP) and Hot Standby Router Protocol (HSRP)
IANA
Internet Assigned Numbers Authority (IANA) assigns public IP addresses to private companies, government entities, and RIRs. Regional Internet Registries
GRE
Generic Router Encapsulation is a tunneling protocol developed by Cisco that encapsulates a wide variety of network layer protocols inside virtual point-to-point links over an Inernet Protocol (IP) network. It allows a routing protocol such as Open Shortest Path First (OSPF) to work between the two offices.
EUI-64
Extended Unique Indetifier-64 is a method used to create a unique 64-bit interface identifier from the 48-bit MAC address of a network interface.
It pads and inserts the host’s MAC address into the interface ID
FTP active and passive move
In FTP’s active mode, when a server needs to transfer a file or information to the client, the information comes from TCP port 20 on the server and is sent to a destination port above TCP 1023 directed to the client. This is communicated through the control channel.
Active mode requires the server to connect back to the client for the data connection, which can be problematic across firewalls and NAT.
Passive mode is designed to alleviate the difficulties encounter with firewalls and NAT, with the client initiating both command and data connections.
MX records
MX records assist a mail server in identifying the mail server for your domain. You must publish an MX record for your mail server if you want to receive mail from other mail servers.
SFP and SFP+
SFP+ transceivers are similar to SFP transceivers, but they can support speeds of 10 Gbps or higher, up to 400 Gbps
What is the purpose of a 110 block in the context of analog wiring of telephone equipment?
The 110 block is used in analog wiring of telephone equipment where it facilitates a cross-connect, leading the connection from one side back to the private branch exchange (PBX) and from the other side to the phone equipment. This is a common setup in on-premises or in-house wiring.
SMB
Server Message Block allows for providing shared access to files, printers, and serial ports among nodes on a network. It can run on wireless networks as well as wired ones.
Cat 8
It is an STP cable that can transmit at 25 Gbps or 40 Gbps and has a maximum distance of 30 meters.
What is the range of IP addresses set aside for multicast addressing?
224.0.0.0 to 239.255.255.255
Anycast IP address
Anycast IP address enables multiservice routing. When a request comes in, it would be directed to the nearest server, enabling sharing and efficient use of resources.
What is the role of the priority in MX records within a domain’s zone file?
In the context of MX records, the priority value isn’t about the importance or sequence of messages. It helps the sending server choose the host to send mail to within a domain, with the lowest priority chosen first.
What is the typical upload speed of the Asymmetrical Digital Subscriber Line (ADSL)?
0.5 Mbps
What is the maximum number of separate channels that can be multiplexed together using Coarse Wavelength Division Multiplexing (CWDM)?
18 channels
What are the two purposes served by fiber distribution panels in a network?
fiber distribution panels help terminate the individual fragile strands to a common fiber-optic connector and also distribute the individual strands.
SFTP
SFTP is used with the SSH protocol, and the command used on many of the systems is scp, which stands for Secure Copy Protocol.
Infrastructure layer
The Infrastructure Layer for a SDN model is where the network hardware such as routers, switches, VPNs or other devices are located, and is directly responsible for data management.
SLACC
In Stateless Address Autoconfiguration, it sends a Router Solicitation (RS) to the multicast address of all routers from the link-local address.
Resource Pooling
According to the NIST, Resource Pooling in cloud computing refers to the practice of time-sharing a pool of computing resources over several virtual instances. Depending on the type of cloud (public or private), the resource pools can be allotted to different customers or within a single organization.
