Chapter 5: Ethernet

Front

What is the operation of Ethernet?

Back

Ethernet is the most widely used LAN technology that operates at the data link layer and the physical layer, defined in the IEEE 802.2 and 802.3 standards. It supports various data bandwidths and relies on two sublayers: Logical Link Control (LLC) and Media Access Control (MAC).

Front

What are the two sublayers of the Ethernet data link layer?

Back

The two sublayers are the Logical Link Control (LLC) and the Media Access Control (MAC) sublayers.

Front

What is encapsulation in Ethernet?

Back

Encapsulation is the process of prepending protocol information with information from another protocol, similar to placing a letter inside an envelope.

Front

What is the minimum and maximum size of an Ethernet frame?

Back

The minimum Ethernet frame size is 64 bytes and the maximum is 1518 bytes.

Front

What is a MAC address?

Back

A MAC address is a 48-bit binary value expressed as 12 hexadecimal digits, used to identify devices on a network.

Front

What are the responsibilities of the MAC sublayer?

Back

The MAC sublayer is responsible for data encapsulation and media access control, which includes frame delimiting, addressing, and error detection.

Front

What is the purpose of the Address Resolution Protocol (ARP)?

Back

ARP resolves IPv4 addresses to MAC addresses and maintains a table of mappings.

Front

What happens when a device needs a MAC address for a destination IP address?

Back

The device sends an ARP request as a broadcast frame to find the MAC address associated with the IPv4 address.

Front

What is the difference between unicast, multicast, and broadcast MAC addresses?

Back

Unicast MAC addresses are unique for one-to-one communication, multicast addresses are used for one-to-many communication, and broadcast addresses are sent to all devices on a local network.

Front

How does a switch learn MAC addresses?

Back

A switch learns MAC addresses by examining incoming frames for new source MAC address information and adding unknown addresses to its MAC address table.