Chapter 4 - Ethernet Basics Flashcards
What was the DIX standard
Enabled multiple computers to connect @ 10 Mbps
Define Ethernet
A standard for a family of network technologies of similar bus topology, frame type, and network access method.
i.e. 10Base2 or 10Base5
What is the purpose of breaking data into frames?
Prevents machines from dominating the bus cable and are more efficient when re transmitting lost data
How do you differentiate between frames and packets
Frames = MAC addresses Packets = IP protocol
What are the 6 pieces of a basic frame
Preamble | Recipient MAC | Senders MAC | Data Type | Pad (if need) | FCS
What is the preamble of a frame
7 byte of alternating 1 and 0 with a 1 byte start frame. This is to let the NIC know a frame is incoming and to know where the frame starts.
What is promiscuous mode`
NIC will analyze all packets regardless of the MAC addresses.
What is the type field of a frame
Helps the receiving computer interpret the frame contents at a basic level.
Will not tell you if it is higher level data (email, etc.)
What is the pad
If a frame if below the minimum 64 bytes the pad will bring the data up to the minimum
what is CSMA/CD
Carrier Sense Multiple Access/Collision Detection.
Its purpose is to determine which computer should use a shared cable. Each cable analyzes the cable before sending.
What happens during a collision
Both transmissions are lost. A randomly generated waiting period is started before sending again.
What is an average number of collisions on a network
Max 10 percent
What is a collision domain
group of nodes that have the capability of sending frames simultaneously
How was a Thicknet network setup
With a thick cable that snaked through the building with a vampire tap used to pierce the cable to connect a workstation.
What ethernet standard was Thicknet
10Base5
What was 10Base2
Thinnet, Connect workstations using a T connector. limited to 185 meters
What was a 10BaseT network
Two or more computers connected to a central hub
What does 10BaseT mean
10 = speed = 10 Mbps Base = Baseband T = Type of cable = Twisted Pair
How many wires does 10BaseT use
pins 1 and 2 to send data
pins 3 and 6 to receive data.
What is another name for a RJ-45 plug
8 position 8 contact modular plug
What is the order of T568A
GW - G - OW - B - BW - O - BrW - B
What is the order of T568B
OW - O - GW - B - BW - G - BrW - B
Give a summary of 10BaseT
Speed: 10 Mbps
Signal: Baseband
Distance: 100 meters
Node Limit : 1024 max
Topology: Star-bus, physical star, logical bus
Cable Type: CAT3 or better, UTP cabling, RJ45 connectors
Give a summary of 10BaseFL
Speed: 10 Mbps
Signal: Baseband
Distance: 2000 meters
Node Limit : 1024 max
Topology: Star-bus, physical star, logical bus
Cable Type: Multimode fiber with ST or SC connectors
How do you connect two hubs
Via the Uplink port OR by using a crossover cable.
Define MDIX
Media dependent interface cross over = uplink port
Define MDI
Media Dependent Interface = regular port
What is a rollover cable
RJ45 on one end and a RS-232 serial port on the other used to connect to cisco switch or router.
What is the purpose of a Bridge
used to connect two ethernet networks AND filters/forwards traffic between segments using MAC addresses
What is the source address table
A swtich copies the source MAC addresses of the frames and creates a table of all the MAC addresses connected.
What is the benefit to Full duplex ethernet
No collisions can occur
Differentiate broadcast domain and a collision domain
Hub based network = collision based domain
Switch based network = broadcast
What is Spanning Tree Protocol
Enables switches to detect loops
