Networking Fundamentals Flashcards
One-to-one transmission
Unicast
One-to-some transmission
Mutlicast
One-to-all transmission
Broadcast
PDU at the Application, Presentation, and Session layer
Data
PDU at the Transport layer
Segment (TCP) / Datagram (UDP)
PDU at the Network layer
Packet
PDU at the Data-Link layer
Frame
PDU at the Physical layer
Bit
TCP/IP Model
Application
Transport
Internet
Link
Three-way handshake to establish session
SYN-SYN/ACK-ACK
Four-way handshake to close session
FIN-ACK-FIN-ACK
TCP flag “URG”
Tell receiver to prioritize this data
TCP flag “ACK”
Acknowledge all TCP segments
TCP flag “PSH”
Tells receiver to directly send this data to the application
TCP flag “RST”
Tells receiver that the sender has abruptly ended the conversation
TCP flag “SYN”
Used in three-way handshake to start conversation
TCP flag “FIN”
Used in four-way handshake to end conversation
Internet Control Message Protocol (ICMP)
An error-reporting protocol used by network devices
Used by ping and traceroute
Address Resolution Protocol (ARP)
Used to map addresses to IP addresses
Sends layer 2 broadcast querying all listening nodes
Mappings are temporarily stored in the devices ARP cache
Does not have assigned protocol numbers
Multiprotocol Label Switching (MPLS)
Internal network used by service providers to create private WAN links for customers
Directs traffic from one node to the next based on short labels instead of long network addresses
Used to speed up the flow of traffic in a network to ensure reliable delivery of data packets
Software Defined WAN (SD-WAN)
Software-defined approach to managing the WAN
Evolved out of MPLS
SD-WAN Architecture
Orchestrator - Optional master software that coordinates multiple SD-WANs
Control Plane - Centralized software that manages the SD-WAN
Forwarding Plane - The physical part of the SD-WAN
Edge - Where network endpoints reside
Multipoint Generic Routing Encapsulation (mGRE)
Point-to-multipoint tunneling between routers
Used in MPLS and SD-WAN networks
Tunneling
To hide a packet inside a packet so it can be transmitted across a certain type of network
Demarcation
Where outside phone-internet services connects to inside wiring
Smart Jack
Placed between demark and customer wiring
Used for remote line diagnostics
vSwitch
Provides switch functionality to virtual machines (VMs)
A host can have many vSwitches, connecting groups of VMs together
Virtual network Interface Card (vNIC)
The network interface that allows a VM to connect to a vSwitch
Hypervisor
A layer of functionality in the host that allows virtual devices to share the hosts physical hardware
Satellite Link
Used when other connection types not available
One satellite covers a large area
Digital Subscriber Line Link (DSL)
Uses existing telephone landline
Requires special modem and user authentication
Cable Link
Uses existing cable TV network
Leased Line Link
Dedicated to a single customer
Metro-optical Link
Optical fibre connecting to providers MAN
