Network Adapters

Question 1

Network interface card

Answer 1

A hardware device that connects a computer to the network medium. It is responsible for converting binary data into a format that can be sent on the network medium. A NIC is also called a network adapter.

Question 2

Gigabit interface converter
(GBIC)

Answer 2

A transceiver that converts electrical signals to optical signals and vice versa in fiber optic and Ethernet systems.

Question 3

Small form-factor pluggable
(SFP)

Answer 3

A transceiver that is similar to a GBIC but is smaller in size. An SFP is sometimes called a mini-GBIC.

Question 4

XFP

Answer 4

A 10-Gigabit small form-factor pluggable transceiver that is similar to an SFP in size but is used for 10-Gigabit networking.

Question 5

QSFP

Answer 5

A quad (4-channel) small form-factor compact hot-pluggable transceiver that is also used for data communication applications.

Question 6

Media access control

Answer 6

A unique identifier burned into the ROM of every Ethernet NIC. The first half of the MAC address (the first six digits) is assigned to each manufacturer. The manufacturer determines the rest of the address, assigning a unique value that identifies the host address.

Question 7

Address Resolution Protocol
(ARP)

Answer 7

A protocol that hosts use to discover the MAC address of a device from its IP address.

Question 8

Reverse Address Resolution Protocol
(RARP)

Answer 8

A protocol that hosts use to find the IP address of a host with a known MAC address.

Question 9

Transceiver module

Answer 9

A transceiver module is used to change the media type of a port on a network device, such as a switch or a router. The following are the most common types of transceiver modules:
A gigabit interface converter (GBIC) is a large transceiver that fits in a port slot and is used for gigabit media, including copper and fiber optic.
A small form-factor pluggable (SFP) is similar to a GBIC, but is a smaller size. An SFP is sometimes called a mini-GBIC.
SFP+ is a newer version of the SFP. SFP+ supports data rates as high as 10 Gbit/s, 8 Gbit/s Fiber Channel, 10 gigabit Ethernet, and the Optical Transport Network (OTU2 standard).
A 10 gigabit small form-factor pluggable (XFP) transceiver is similar to an SFP in size, but is used for 10 gigabit networking.
Quad (4-channel) SFP is a compact hot-pluggable transceiver that is also used for data communication applications.

Question 10

Media converter

Answer 10

You use a media converter to connect network interface cards that are using different media types. For example, a media converter could be used to connect a server with a fiber optic Ethernet NIC to a copper Ethernet cable.
Media converters work at the Physical layer (Layer 1). Media converters do not read or modify the MAC address in any way.
Media converters convert one media type to another within the same architecture (such as Ethernet). A media converter cannot translate between two different architectures. This must be done using a bridge or a router. Converting from one architecture to another requires modifying the frame contents to modify the Data Link layer address.

Question 11

Media access control (MAC) address

Answer 11

A MAC address is a unique identifier burned into the ROM of every Ethernet NIC.
The MAC address is a 12-digit (48-bit) hexadecimal number (each number ranges from 0–9 or A–F).
The address is often written as 00-B0-D0-06-BC-AC or 00B0.D006.BCAC. Dashes, periods, and colons can be used to divide the MAC address parts.
The MAC address is globally unique by design. The first half of the MAC address, the first six digits, is assigned to each manufacturer. The manufacturer determines the rest of the address, assigning a unique value that identifies the host address. A manufacturer that uses all the addresses in the original assignment can apply for a new MAC address assignment.
Devices use the MAC address to send frames to other devices on the same subnet.
Some network cards allow you to change the MAC address through jumpers, switches, or software, but there are few legitimate reasons for doing so.

Question 12

Address Resolution Protocol
(ARP)

Answer 12

Hosts use ARP to discover the MAC address of a device from its IP address. Before two devices can communicate, the MAC address of the receiving device must be known. If the MAC address isn’t known, ARP does the following to find it:
The sending device sends out a broadcast frame.
The destination MAC address is all Fs (FFFF:FFFF:FFFF).
The sending MAC address is its own MAC address.
The destination IP address is the known IP address of the destination host.
The sending IP address is its own IP address.
All hosts on the subnet process the broadcast frame, looking at the destination IP address.
If the destination IP address matches its own address, the host responds with a frame that includes its own MAC address as the sending MAC address.
The original sender reads the MAC address from the frame and associates the IP address with the MAC address, saving it in its 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 cyclic redundancy check (CRC) that is used to detect frames that have been corrupted during transmission.

Hosts use the reverse address resolution protocol (RARP) to find the IP address of a host with a known MAC address.