Ethernet Basics CH 4 Flashcards
What is sneaker-net?
This was a term used to describe. Saving data to a floppy putting on your shoes and walking to the next computer.
What is a Hub?
Receives data on one port and repeats it to all other ports except the originating port.
Note: Reads incoming signal and sends new copies of that signal out to every connected port.
What is a Preamble of a frame?
a 7-byte series of alternating ones and zeroes followed by a 1-byte Start Frame. Gives NIC time to realize a frame is coming and to know exactly where the frame starts.
What adds the Preamble?
The sending NIC
48-bit (6-Byte) address is also known as what?
MAC address
Why would a system have two MAC addresses?
The system has more then one NIC
What is Promiscuous mode
NIC processes all the frames it sees on the cable regardless of their MAC addresses.
What is a Type of a frame?
Helps the receiving computer interpret the frame contents at a very basic level.
What is a Data of a frame?
Contains payload the frame carries.
What is a Pad of a frame?
the min size of a ethernet frame is 64 bytes. pad is extra data to created by the NIC to make the packet a min of 64 bytes.
What is FCS
FCS (Frame Check Sequence) special code attached to each frame that helps determine the integrity of data.
Carrier sense multiple access/collision detection determines what?
Which computer should use a shared cable at a given moment.
When Two NICs send at the same time what happens?
A collision occurs, the hub sends out the overlapping signals, and the NIC detects the collision.
After a Collision occurs and a NIC detects the collision what happens?
The NIC generates a random number and waits for that period of time, the NIC with the lowest number will start generating traffic and avoid a collision.
what is a collision domain?
a group of nodes that have the capability of sending frames at the same time as each other resulting in collisions.
What is 10Base2 or Thinet?
Use RG-58 coaxial cable with BNC connections on the end.
Uses a Bus topology.
Uses a T connector to connect to the BUS.
What must you do with a 10Base2 (thinnet) connection
Terminate at the ends of the BUS
10Base2 Networks can be used at a maximum distance of what?
185 Meters
10Base5 Networks can be used at a maximum distance of what?
500 Meters
What is the minimum CAT standard cable that can be used with a 10BaseT?
Cat3 or higher
What should you check first when investigating an outage with multiple systems on a 10BaseT network?
The HUB
NICs that can only communicate in one direction at a time run in what mode?
Half Duplex
NICs that can send and receive at the same time are in what mode?
Full Duplex
What TIA/EIA standard is this?
Orange/White 1 | Orange 2 | Green/White 3 | Blue 4 | Blue/White 5 | Green 6 | Brown/White 7 | Brown 8 |
568B
What TIA/EIA standard is this?
Green/White 1 | Green 2 | Orange/White 3 | Blue 4 | Blue/White 5 | Orange 6 | Brown/White 7 | Brown 8 |
568A
List the 8 colors in order using the 568B Standard
Orange/White | Orange | Green/White | Blue | Blue/white | Green | Brown/White | Brown |
List the 8 colors in order using the 568A Standard
Green/White 1 | Green 2 | Orange/White 3 | Blue 4 | Blue/White 5 | Orange 6 | Brown/White 7 | Brown 8 |
10BaseFL uses what type of cabling?
Fiber-Optic
What are the reasons to use Fiber Optic cables??
Up to 2km Distance, EMI is not a factor, Security(much harder to wire tap)
What is a MDI?
Media dependent interface is a regular port on a switch or a hub
what is MDIX?
Media dependent interface crossover (MDIX) is an uplink port
How do you create a cross over cable?
Reversing cables on pins 1,2,3,6 from the other side of the wire. One end is wired according to 568A and the other is according to 568B
Crossover cables connect in _______ Port?
Standard port
What is a straight through cable?
has both cable standards (568A, 568B) of the RJ-45 connector using Twisted Pairs
What is a rollover cable?
Has an RJ-45 connector on one end and a class RS-232 serial port on the other.
How does a Bridge work?
Acts like a repeater to connect two Ethernet networks, But goes one step beyond -filtering and forwarding traffic between those segments based on the MAC address of the computers on those segments. (Preserves Bandwidth)
What Layer of the OSI model do Bridges work?
Networking Layer 3
