Ethernet Basics

Question 1

Coined by Xerox for the first standard of network cabling and protocols. It is based on a bus topology.

Answer 1

Ethernet

Question 2

How where these challenges solved:
How to send data across the wire?
How to identify the sending and receiving computers?
How to determine which computer should use the shared cable at what time?

Answer 2

Using data frames that contain MAC addresses to identify computers on the network and by using a process called CSMA/CD

Question 3

Frames address what two networking issues?

Answer 3

• Prevent any single machine from monopolizing the shared bus cable
• they make the process of retransmitting lost data more efficient

Question 4

A 64-bit (7byte) series of alternating 1’s and 0s ending with 11 (1 byte) Start Fame. It gives a receiving NIC time to realize a frame is coming and to know exactly where the frame starts

Answer 4

Preamble

Question 5

Diagnostic program that can order a NIC to run in promiscuous mode.

Answer 5

Sniffer

Question 6

A mode of operation for a NIC in which the NIC processes all frames that it sees on the cable

Answer 6

Promiscuous Mode

Question 7

Name the six pieces of information that a basic Ethernet frame contains

Answer 7

Preamble
MAC Addresses - where its going where it came from
Type - IPv4 or IPv6
Data - whatever payload the frame carries
Pad - ethernet hold 64 bytes if less then a pad extra
data will be inserted to bring it up to 64 bytes
FCS- checks to make sure the calculation match from
the beginning to the end

Question 8

Access method that Ethernet systems use in wired LAN technologies, enabling frames of data to flow through the network and ultimately reach address locations. Hosts on _____ network first listen to hear if there is any data on the wire. If there is none, they send out data. If a collision occurs, then both hosts wait a random time period before retransmitting the data

Answer 8

CSMA/CD (Carrier Sense Multiple Access with Collision Detection)