Network+ Chapter 4: Ethernet Basics Page 85-92

Node (NIC): A member of a network or a point where one or more functional units interconnect transmission lines

            - Must have a unique identifying address
            - Identified using 48-bit binary addresses known as Mac Addresses

Mac Address: Unique 48-bit address assigned to each network card. IEEE assigns blocks of possible addresses to various NIC manufacturers to help ensure that each address is unique. The Data Link layer of the OSI seven-layer model uses MAC addresses for locating machines.

           - give each NIC a unique address
           - computers on the network listen to the wire to see if it contains their MAC address
           - if a machine sees it's address it opens the frame to process data

Sniffers: Diagnostic program that can order a NIC to run in a promiscuous mode.
           - Ethernet provides no protection against sniffers
Promiscuous Mode: A mode for a NIC in which the NIC processes all frames that it sees on the cable.

Frame: A defined series of binary data that is the basic container for container for a discrete amount of data moving across a network. Frames are created at Layer 2 of the OSI model.
           - computers can determine what type of data (IPv4 or IPv6)
           - type field does not tell you if the fram carries an email or web page

Data:
           - contains whatever payload the frame carries
         
Pad:
           - minimum Ethernet frame is 64 bytes (but not all has to be data)
           - if fewer than 64 bytes in size, the sending relay will automatically add extra data

Frame Check Sequence:
           - Ethernet's term for the cyclic redundancy check
           - Enables Ethernet nodes to recognize when bad things happen to good data
           - machines must be able to detect when data has been damaged
       
CSMA/CD:
           - Carrier sense multiple access/collision detection
           - determines which computer should use a shared cable
           - means that each node using the network examines the cable before sending data
           - network access method that maps to the IEEE 802.3 standard for Ethernet networks
           - multiple access means that all machines have equal access to the wire
           - collision domain is a group of nodes that have the capability of sending frames at the same time as each other
         

10BaseT:
            - created in 1990
            - 10 Mbps
            - signaling type: baseband
            - the cable only carries one type of signal
            - uses twisted pair cable
            - RJ-45 connector
            - enables devices to put voltage on the individual wires within the cable
            - designates some of these numbered wires for specific