Foundational Networking Tech Flashcards
What is the Access Layer
The layer in Three-Tier Architecture, wiring from Ethernet wall jacks terminate into switches at this layer. In a multi-floor building, each floor may have its own access layer switches.
What is an Ad Hoc Wireless LAN?
An on-demand type of wireless connection where a client connects directly to another client or device w/o having to connect to a Wi-Fi access point or router.
What is an Angled Physical Contact (APC) Connector?
A connector used in fiber optic cabling which has a fiber end face polished at an 8-degree angle. The angled end face causes reflected light to travel at an angle into the cladding, rather than traveling back to the light source.
What is attenuation?
A reduction in the strength of a signal being transmitted. This is a natural consequence of sending signals over long distances, and is the primary reason for distance limitations placed on network cables.
What is a Basic Service Set Identifier (BSSID)?
The unique 48-bit identifier for a single wireless router or access point that follows MAC address conventions.
What is a Bidirectional (BiDi) Transceiver?
A fiber optic module which can simultaneously send and receive data over a single strand by using different light wavelengths for each.
What is a BNC Connector?
A type of connector found on 50 or 75 Ohm coaxial cable. This was commonly found in older thin coaxial cable networks, capable of operating at a speed of 10 Mbps.
What is Carrier-Sense Multiple Access w/ Collision Detection (CSMA/CD)
A set of rules used to detect and avoid data collision on a network. These rules determine how network devices react when they are attempting to simultaneously use a shared data channel, such as in a Shared Media network.
Category 3 (CAT3) cables
Twisted-pair cabling w/ a maximum of 100 Mbps, and a distance limitation of 10 meters
Category 5 (CAT5) cables
Twisted-pair cabling w/ a maximum of 1 Gbps, and a distance limitation of 100 meters
Category 5e (CAT5e) cables
Twisted-pair cabling w/ a maximum of 1 Gbps, and a distance limitation of 100 meters. The wires are more tightly twisted than CAT5, creating less crosstalk interference.
Category 6 (CAT6) cables
Twisted-pair cabling w/ a maximum of 10 Gbps. It has a distance limitation of 100 meters when transmitting at 1 Gbps, or 55 meters when transmitting at 10 Gbps.
Category 6a (CAT6a) cables
Twisted-pair cabling w/ a maximum of 10 Gbps, and a distance limitation of 100 meters. Compared to its predecessor (CAT6), there is more shielding to allow the 10 Gbps transmission rate over a longer distance.
Category 7 (CAT7) cables
Twisted-pair cabling w/ a maximum of 10 Gbps, and a distance limitation of 100 meters. Also has the ability to carry voice, video, and data simultaneously.
Describe the Cisco DNA Center
An appliance that provides a graphical interface and a programming interface for network design, device configuration, network monitoring, and troubleshooting.
What is cladding?
The fiber optic cable layer which surrounds the inner core, made from glass or plastic that is less transparent than the core. The refractive index difference b/t the core and the cladding creates a mirror-like surface which guides the light signal along the core.
Client-Server Architecture
A network architecture model in which a server hosts and manages resources on a network, providing access for clients
Cloud Architecture
A network architecture where resources are stored on a hosted solution and accessed over the public internet. The hosted solution provider is responsible for all costs associated w/ keeping the data center running securely and efficiently, which is one upside to this model
Coaxial Cable
A type of copper cable built w/ metal shielding in order to reduce signal interference, commonly used w/ cable television installations.
Collapsed Core Architecture
A two-tier topology used in smaller networks where the Core and Distribution layers have been consolidated, creating an Access layer and a Collapsed Core layer.
Collapsed Core Layer
The layer in Collapsed Core Architecture which combines the functions of the Three-Tier Architecture Core layer and Distribution layer.
Core (in cabling)
The center of a fiber optic cable used to transfer light signals. Depending on the grade of the cabling this may be made from plastic or glass, w/ plastic cores providing affordability and cable flexibility, and glass cores providing the best performance
Core Layer
The layer in Three-Tier Architecture which interconnects all of the core layer switches. In a multi-building campus, this would be a centralized building which uses multi-layer switches to interconnect distribution layers from all other buildings
Crossover cable
A twisted-pair copper cable that uses a crossed over wire pinout in the RJ-45 connector on each end. The pins designated as the send pins on one end are designated as the receive pins on the other end, and vice versa
Crosstalk
The unwanted signals in a communication channel caused by the transfer of energy from another source.
Customer Edge (CE) Routers
In an MPLS network, these devices sit at the edge of each local network, providing a gateway to the MPLS service provider cloud.
DB-25 Connector
A type of 25-pin connector commonly used for early serial and parallel ports
DB-9 Connector
A type of 9-pin connector commonly used w/ serial ports
Default Route
The route used when more specific info. about a destination IP address is not available, identified by the IPv4 address 0.0.0.0/0 and the IPv6 address ::/0
Distribution Layer
The layer in the Three-Tier Architecture which connects all of the access layer switches. In a multi-floor building, this would be a central point where multilayer switches are used to aggregate access layer switch traffic
EIA/TIA T568B Standard
The most common twisted-pair cable wiring standard used in the networking and telecom industries. There is also a T568A standard, w/ only difference being that pairs 2 and 3 (orange and green) are swapped
Electromagnetic Interference (EMI)
Interference that occurs when radio waves are picked up or radiated by a cable carrying another signal, resulting in signal degradation.
Endpoint
A device that connects to a network in order to utilize resources such as Internet access, file shares, or network printers. Also referred to as a client.
Extended Service Set Identifier (ESSID)
The collection of basic services set identifiers (BSSIDs) that make up a network, representing the primary name associated w/ the wireless LAN. This term is rarely used and represents the same thing as the SSID, which is the preferred term
F-Type Connector
A coaxial connector commonly used for terrestrial television, cable television, and satellite, found on RG-6 and RG-59 coaxial cable
Gigabit Interface Converter (GBIC)
A module used in fiber optic and Ethernet systems as in interface for high-speed networking, w/ a data transfer rate of 1 Gbps
Hypervisor
A software running on a virtual server that is used to create, start, stop, and monitor multiple virtual machines
IEEE 802.3af
The original Power over Ethernet (PoE) standard which provides up to 15.4 Watts of power to a device
IEEE 802.3at
An update to the original Power over Ethernet (PoE) standard which provides up to 25.5 Watts of power to a device
IEEE 802.3bt
The most recent Power over Ethernet (PoE) standard which can provide up to 100 Watts of power to a device
Impedance
The measure of a circuit’s resistance to current flow, represented in Ohms
Infrastructure Wireless LAN
A wireless topology commonly seen in small offices and homes, where a wireless router is connected directly to an Internet Service Provider (ISP) device such as a cable or fiber modem in order to provide wireless clients access to the public Internet
Intrusion Prevention System (IPS) Sensor
An appliance that sits inline w/ traffic and checks that traffic against a database of known threats. If a threat is detected, the offending packets can be dropped
Jacket
The outermost layer of a fiber optic cable, made from polymer and used to protect the core and cladding from physical damage
Jitter
The time gap b/t packets in a data flow. The amount of acceptable jitter is dependent on the application, but is especially problematic in IP telephony and video conferencing
Label Switch Router (LSR)
Routers round w/n the MPLS service provider cloud. They can make forwarding decisions based on MPLS labels rather than IP addresses
Lambda
An individual wavelength of light used for transmitting data on a fiber-optic network. Traffic from multiple customers can be separated by providing each of them w/ a different Lambda value for their traffic
Latency
A general term for any kind of delay that happens during data communication on a network. High latency creates bottlenecks, effectively decreasing communication capabilities
LC Connector
A connector used in fiber optic cabling which carries a single strand of fiber and uses a locking tab coupler
MAC Address Table
A table of corresponding interfaces and MAC addresses used by a switch to determine where data frames should be directed in a network
Media Access Control (MAC) Address
A 48-bit address burned into a network interface card by the manufacturer
Media Dependent Interface (MDI)
A type of Ethernet port in low bandwidth networks (10 Mbps - 100 Mbps) which is only two twisted pairs of an Ethernet cable (4 wires) for data flow. MDI ports use pins 1 and 2 to transmit, and pins 3 and 6 receive
Media Dependent Interface Crossover (MDIX)
A type of Ethernet port connection that enables communications b/t two devices w/ straight-through twisted pair cable, ensuring that they are not transmitting and receiving data on the same set of wires
Mesh Wireless LAN
A system of multiple wireless mesh nodes which have the ability to communicate w/ one another in order to direct wireless client traffic. Mesh nodes do not have to be connected into a switch in order to operate.
Metropolitan Area Network (MAN)
A network that interconnects nodes w/n a large geographical region. These are Larger than a LAN, but smaller than the area covered by a WAN
MT-RJ Connector
A connector used in fiber optic cabling which contains two fiber strands, allowing a higher port density by having transmit and receive strands in the same connector
Multimode Delay Distortion
A condition in multimode fiber that happens due to the multiple paths of light traveling w/n the core. Because the angles internal reflection can vary in multimode fiber, it’s possible for data to arrive out of order or w/ a delay
Multimode Fiber
Fiber optic cabling that has large diameter core, allowing multiple paths for light to travel through. The larger diameter allows for more light reflections inside the core, allowing more data to pass through at a given time. However, due to the high dispersion rate of the light, the signal cannot travel over long distances
Multiprotocol Label Switching (MPLS)
A routing technique that directs data frames b/t nodes based on labels, rather than using network addresses. On high-speed networks, this helps ensure fast traffic by eliminating routing table lookups
Next Generation Firewall (NGFW)
An Application Layer firewall w/ advanced features such as deep-packet inspection (DPS) , intrusion prevention systems (IPS), and encrypted traffic inspection. Also referred to as a Layer 7 firewall
On-Premise Architecture
A network architecture where all resources are contained w/n the organization itself, or w/n an organizationally owned data center. This is the more traditional manner for deployment, as opposed to cloud architecture
Peer-to-Peer Architecture
A network architecture model in which each client has the ability to share its resources w/ other clients on the network, w/o the use of a centralized server
Plenum-Rated Cable
Cabling that uses a special insulation w/ low smoke and low flame characteristics. This is mandatory for any installations where the cabling must be routed through an air handling space, such as a drop ceiling
Point-to-Multipoint
A type of WAN connection used to provide multiple paths from a central location out to multiple other locations, such as interconnecting all branch sites back to a main office. Frame Relay is a common tech. used for this type of connection
Point-to-Point
A type of WAN connection that interconnects two devices, typically using a Layer 2 protocol. The Point-to-Point Protocol (PPP) is a common Layer 2 protocol used to establish these connections.
Power over Ethernet (PoE)
A technology that delivers power and data over a single Ethernet cable, allowing devices such as IP phones and cameras to be easily deployed and powered.
Power Source Equipment (PSE)
In a Power over Ethernet (PoE) deployment, this is the device sourcing the power, such as a Cisco Catalyst switch.
Powered Device (PD)
In a Power over Ethernet (PoE) deployment, this is the device requiring power, such as an IP phone or camera.
Provider Edge (PE) Routers
Also referred to as Edge Label Switch Routers (ELSR), these routers sit at the edge of the MPLS service provider cloud. They can make forwarding decisions based on MPLS labels rather than IP addresses.
Quad Small Form-Factor Pluggable (QSFP)
A fiber optic module that bundles together 4 links for higher throughput rates. A QSFP bundles together 4 SFP modules, for a throughput of 4 Gbps. A QSPF+ bundles together 4 SFP+ modules, for a throughput of 40 Gbps.
RG-59 Cable
A type of coaxial cable used for low-bandwidth, low-frequency applications such as analog television and CCTV. This cabling has an impedance of 75 Ohms.
RG-6 Cable
A common type of coaxial cable used in residential applications, which has an impedance of 75 Ohms. This is an improvement over older RG-59 cabling with better insulation and shielding for use with high-bandwidth, high frequency applications such as Internet and television.
RJ-11 Connector
A type of connector commonly used in telecommunications which has 6 positions with 2 conductors
RJ-45 Connector
A type of connector commonly used for Ethernet networking which has 8 pins with 8 conductors.
Router
A device that makes packet forwarding decisions based on destination IPv4 or IPv6 addresses.
Routing Table
A table of corresponding interfaces and IP addresses used by a router to determine where data packets should be directed in a network.
SC Connector
A connector used in fiber optic cabling which carries a single strand of fiber and uses a push-pull coupler
Server
A device running a specialized software setup as a centralized repository of resources that can be accessed by clients on a network.
Service Set Identifier (SSID)
The primary name associated with a wireless LAN, used to distinguish it from other nearby wireless networks.
Shared Media Nwtwork
A network connected as a bus topology, where the network nodes are connected into a single backbone cable.
Shielded Twisted-Pair Cable
Cabling that uses an outer covering of foil or wire braiding to enclose twisted pairs of wires, supporting higher transmission rates and better protection from electromagnetic interference (EMI).
Shim Header
A 32-bit value used to make forwarding decisions when using MPLS. This value is inserted between the Layer 2 and Layer 3 headers of a frame, and is also referred to as an MPLS label.
Single-Mode Fiber
Fiber optic cabling that has a small diameter core, allowing only one path for light to travel through. The smaller diameter creates fewer light reflections inside the core, creating the ability for the signal to travel further.
Small Form-Factor Pluggable (SFP) Transceiver
A fiber optic module that plugs into a physical port of a network device, used with small form-factor connectors. These are hot swappable and offer physical compactness, with speeds of 1 Gbps.
Small Form-Factor Pluggable Plus (SFP+) Transceiver
Virtually identical to a normal SFP transceiver, with the primary difference being that this updated version supports higher speeds up to 10 Gbps.
Small Office/Home Office (SOHO) Topology
A type of network commonly found in small businesses and homes, which consists of a limited amount of network infrastructure on the LAN. This can be a mixed network of wired and wireless devices.
Spine-Leaf Architecture
A two-tier topology used in data centers, where the leaf layer consists of access layer switches fully meshed to a series of multilayer switches that make up the spine layer.
ST Connector
A quick release bayonet style connector used in fiber optic cabling, which carries a single strand of fiber and uses twist-lock coupler.
Straight-Through Cable
A twisted-pair copper cable that uses the same pinout in the RJ-45 connectors at each end.
Switch
A device that makes frame forwarding decisions based on destination MAC addresses.
Three-Tier Architecture
A network topology divided into the Access, Distribution, and Core layers.
Transmission Control Protocol (TCP)
A network communication protocol that provides reliable, connection-oriented delivery of data packets. TCP uses a 3-way handshake in order to establish a connection between two nodes.
Twisted-Pair Cable
A type of cable made by putting two separate insulated wires together in a twisted pattern and running them parallel to each other, commonly thought of as Ethernet cabling.
Type-1 Hypervisor
Also referred to as a “Native hypervisor” or a “Bare Metal hypervisor”. A type of hypervisor that runs directly on the server’s hardware, with direct access to the underlying hardware resources.
Type-2 Hypervisor
A type of hypervisor that runs in a traditional operating system. Also referred to as a hosted hypervisor.
Ultra Physical Contact (UPC) Connector
A connector used in fiber optic cabling which has a polished fiber end face with a very slight, nearly flat curvature. Any light that is reflected will travel straight back toward the light source.
Unshielded Twisted-Pair (UTP) Cable
Cabling that relies on the twists of the paired wires to protect from electromagnetic interference (EMI).
User Datagram Protocol (UDP)
A network communication protocol that provides unreliable best-effort delivery of data packets. This is used for latency-sensitive connections where some data loss may be tolerated, such as with voice over IP (VoIP) traffic.
Virtual Machine (VM)
A software emulation of a computer system which has the ability to operate like a physical computer.
Virtual Network Interface Card (NIC)
Software associated with a unique MAC address, which can be used by a virtual machine to send and receive packets.
Virtual Private Network (VPN)
A method for providing network security through the use of an encrypted tunnel, creating a private network from a public Internet connection.
Virtual Server
A server that shares hardware and software resources with multiple virtualized devices and operating systems.
Wide Area Network (WAN)
A geographically dispersed network that is used to interconnect multiple local area networks (LANs).
Wireless Access Point (WAP)
A device connected directly to the LAN which provides network access to wireless clients.
Wireless LAN Controller (WLC)
A device used as a centralized management point for wireless networks, into which wireless access points (WAPs) are connected.
