Chapter 2 - Ethernet Networking and Data Flashcards
Describe the operation of Carrier Sense Multiple Access with Collision Detection (CSMA/ CD).
CSMA/ CD is a protocol that helps devices share the bandwidth evenly without having two devices transmit at the same time on the network medium. Although it does not eliminate collisions, it helps to greatly reduce them, which reduces retransmissions, resulting in a more efficient transmission of data for all devices.
Differentiate half-duplex and full-duplex communication and define the requirements to utilize each method.
Full-duplex Ethernet uses two pairs of wires at the same time instead of one wire pair like half-duplex. Full-duplex allows for sending and receiving at the same time, using different wires to eliminate collisions, while half-duplex can send or receive but not at the same time and still can suffer collisions. To use full-duplex, the devices at both ends of the cable must be capable of and configured to perform full-duplex.
Describe the sections of a MAC address and the information contained in each section.
The MAC, or hardware, address is a 48-bit (6-byte) address written in a hexadecimal format. The first 24 bits, or 3 bytes, are called the organizationally unique identifier (OUI), which is assigned by the IEEE to the manufacturer of the NIC. The balance of the number uniquely identifies the NIC.
Identify the binary and hexadecimal equivalent of a decimal number.
Any number expressed in one format can also be expressed in the other two. The ability to perform this conversion is critical to understanding IP addressing and subnetting. Be sure to go through the written labs covering binary to decimal to hexadecimal conversion.
What are the 7 fields in the Data Link portion of an Ethernet frame?
- Preamble
- Start Frame Delimiter
- Destination MAC address
- Source MAC address,
- Length or Type
- Data
- Frame Check Sequence.
Identify the IEEE physical standards for Ethernet cabling.
These standards describe the capabilities and physical characteristics of various cable types and include but are not limited to 10Base-2, 10Base-5, and 10Base-T.
Differentiate types of Ethernet cabling and identify their proper application.
The three types of cables that can be created from an Ethernet cable are straight-through (to connect a PC’s or router’s Ethernet interface to a hub or switch), crossover (to connect hub to hub, hub to switch, switch to switch, or PC to PC), and rollover (for a console connection from a PC to a router or switch).
Describe the data encapsulation process and the role it plays in packet creation.
Data encapsulation (also called packet creation) is a process whereby information is added to the frame from each layer of the OSI model. Each layer communicates only with its peer layer on the receiving device.
Understand how to connect a console cable from a PC to a router and switch.
Take a rolled cable and connect it from the COM port of the host to the console port of a router. Start your emulations program such as putty or SecureCRT and set the bits per second to 9600 and flow control to None.
Identify the layers in the Cisco three-layer model and describe the ideal function of each layer.
The three layers in the Cisco hierarchical model are the core (responsible for transporting large amounts of traffic both reliably and quickly), distribution (provides routing, filtering, and WAN access), and access (workgroup connectivity into the distribution layer).
