Vol I Ch 2 Fundamentals of Ethernet LANs

Question 1

Strait-Through cable Pinout

Answer 1

Transmit on pins 1 and 2

Receive on pins 3 and 6

Question 2

Crossover cable Pinout

Answer 2

Pin 1 crossed to pin 3

Pin 2 crossed to pin 6

Question 3

Which 10BASE-T and 100BASE-T devices transmit on pins 1 and 2?

Answer 3

PC NICs
Routers
Wireless Access Points Ethernet Interface

Question 4

Which 10BASE-T and 100BASE-T devices transmit on pins 3 and 6?

Answer 4

Hubs

Switches

Question 5

1000BASE-T Pinout

Answer 5

Transmit 1 and 2
Receive on pines 3 and 6
Transmit on pins 4 and 5???
Receive on pins 7 and 8???

Question 6

LED

Answer 6

Light used in multimode fiber with internal reflection

Question 7

Laser

Answer 7

Light used in Single-Mode fiber

Question 8

Size of data and pad in an Ethernet frame

Answer 8

46 bytes minimum to 1500 bytes maximum.

Question 9

Ethernet type field or EtherType

Answer 9

Helps network processing on routers and hosts.
Identifies the type of network layer (layer 3) packet that sits inside the Ethernet frame.
Today, it identifies the most common network layer protocols: IPv4 and IPv6.
The original host inserts a hexadecimal value.
0800 = IPv4
86DD = IPv6

Question 10

FCS

Answer 10

Frame Check Sequence in the Ethernet trailer to find out whether a frame’s bits changed.
This is error detection, not error recovery.

Question 11

LAN hub

Answer 11

Layer 1 device.

Repeater.