Network Adapter Facts

Question 1

Network Adapter

Answer 1

• aka NIC
• Connects a host to the network medium
• Responsible for converting binary data into a format to be sent on the network medium

Question 2

Transceiver

Answer 2

• Is responsible for converting digital data into digital signals to be sent on the medium
• Fiber optic NIC sends light signals
• Wired NIC sends electronic signals on a wire
• Wireless NIC sends radio signals
• To receive signals, the transceiver converts digital signals from the network to digital data for the PC

Question 3

Modem

Answer 3

• Converts binary data to analog waves (modulation) on the sending end, and the converts the analog waves back to binary data ( demodulation) on the receiving end

Question 4

Network Adapter Facts

Answer 4

• Network Adapters are layer 1 devices because they send and receive signals on the network medium
• Network Adapters are also layer 2 devices because they must follow the rules for media access, and because they read e physical address in a frame

Question 5

Components used by a network adapter

Answer 5

• Transceiver Module
• Media Converter
• MAC Address
• Address Resolution Protocol (ARP)

Question 6

Transceiver Module

Answer 6

• Used to change the media type of a port on a network device, such as a switch or router

Question 7

Common types of transceiver modules

Answer 7

• GBIC (Gigabit interface converter)
• SFP ( Small form-factor pluggable)
• XFP

Question 8

GBIC (Gigabit interface converter)

Answer 8

• A larger-sized transceiver that fits in a port slot and is used for Gigabit media including copper and fiber optic

Question 9

SFP (Small form-factor pluggable)

Answer 9

• Similar to GBIC but is a smaller size

* Sometimes called a mini-GBIC

Question 10

XFP

Answer 10

• Is similar to an SFP but is used for 10 Gigabit networking

Question 11

Media Converter

Answer 11

• Used to connect network adapters that are using different media types
• Ex. could be used to connect a server with fiber optic Ethernet NIC to copper Ethernet cable

Question 12

Media Converter Facts

Answer 12

• Work at the Physical layer
• Do not read or modify the MAC address in any way
• Only convert from one media type to another within the same architecture (such as Ethernet)
• Can’t transfer from different architectures (needs to be done by bridge or router)

Question 13

MAC Address

Answer 13

• is a unique identifier burned into the ROM of every Ethernet NIC

Question 14

MAC Address Facts

Answer 14

• 12-digit (48 bit) hexadecimal number (0-9 or A-F)
• Can be written as 00-B0-06-06-BC-AC or OOBO.D006.BCAC
• Globally unique by design - first half is assigned to the manufacturer - last 6 digits manufacturer determines
• Devices use MAC Addresses to send frames to other devices on the same subnet

Question 15

Address Resolution Protocol (ARP)

Answer 15

• Used by host to discover the MAC address of a device from its IP address.
• Before two devices can communicate they must know the MAC address of the receiving device
• If MAC address is unknown then ARP finds it

Question 16

Steps of ARP

Answer 16

• Sends device a broadcast frame
• Destination MAC address is all Fs (FFFF:FFFF:FFFF)
• The sending MAC address is its own MAC address
• Destination IP address is the known IP address of the destination host
• Sending IP address is its own IP address
• All host on subnet process the broadcast by looking at destination IP address
• If destination OP address matches its own address the host responds with a frame that includes is own MAC address as the sending MAC address
• Original sender reads the MAC address from the frame and associates the IP address with the MAC address, saving it in the cache
• Once the sender knows the MAC address of the receiver it sends data in frames addressed to the destination device. These frames include a CRC

Question 17

Cyclic Redundancy Check (CRC)

Answer 17

• Used to detect frames that have been corrupted during transmission

Question 18

Reverse Address Resolution Protocol (RARP)

Answer 18

• Used to find the IP address of a host with a known MAC address