5.1 Layer 2 Switching Overview

Question 1

What is an access switch?

Answer 1

is a switch that gives users access to the local area network. These switches send data to and from specific computers or nodes that are connected to them.

Question 2

What is a distribution switch

Answer 2

is a switch that resides in the distribution layer and connects to the access and core switches. Distribution switches are linked to each other via high-speed connections, often a 10 Gb Ethernet connection.

Question 3

What is a core switch

Answer 3

is a switch that resides in the core layer of a two-tier architecture. Most core switches are typically placed in the same location as other distribution switches and connected to the distribution switches.

Question 4

What is a two-tier architecture

Answer 4

also known as a collapsed core design, is a switch architecture designed with an access layer, which contains access switches, and a distribution layer, which contains distribution switches.

Question 5

What is a three tier architecture

Answer 5

is a switch architecture designed with an access layer, a distribution layer, and a core layer. The purpose of this core layer is to connect the distribution switches.

Question 6

What is a Two-tier spine-and-leaf architecture

Answer 6

is a switch architecture designed with a leaf layer and a spine layer used in data centers.In the leaf layer, every access switch is connected to each of the switches in the spine layer creating a full mesh topology. The spine layer is made up of switches that perform routing and is the backbone of the network.

Question 7

What is the three-tier-spine-and-leaf

Answer 7

is a switch architecture designed with a leaf layer, a spine layer, and a core layer used in data centers. The core layer consists of routers added to the leaf and spine layers. A spine-and-leaf architecture allows data flows to take shortcuts from where data is, to where it is going.

Question 8

What is a Content Addressable Memory Table (CAM)

Answer 8

A forwarding database with a list of MAC addresses and the ports used to reach the device

Question 9

Unicast

Answer 9

A unicast frame is sent to a single recipient

Question 10

Broadcast

Answer 10

A broadcast frame is sent to all interfaces on the same physical network segment

Question 11

Multicast

Answer 11

A multicast frame is sent to multiple recipients.

Question 12

What is LAN segmentation?

Answer 12

is the process of dividing the network into segments to overcome problems such as excessive collisions, broadcast traffic, or heavy network traffic. By segmenting a LAN, you can increase network performance, maximize bandwidth, and reduce congestion.

Question 13

What is a collision domain?

Answer 13

any network or subnetwork where devices share the same transmission medium and where packets can collide

Question 14

What is a broadcast domain

Answer 14

is any network or subnetwork where computers can receive frame-level broadcasts from their neighbors.

Question 15

When should you use a bridge?

Answer 15

to segment the network (divide network traffic) and to provide fault tolerance

Question 16

When should you use a switch?

Answer 16

to reduce collisions and offer guaranteed bandwidth between devices

Question 17

When should use a router

Answer 17

to filter broadcast messages, implement security, or connect different networks

Question 18

Explain the switch forwarding method Cut-Through

Answer 18

Reads the frame until it gets to the destination MAC address and copies it into its buffer.
Begins forwarding the packet without verifying frame integrity.

Question 19

Explain the switch forwarding method Fragment-free

Answer 19

Reads the first 64 bytes of a frame.
Verifies that the packet is not fragmented by a collision.
Forwards non-fragmented frames.

Question 20

Explain the switch forwarding method Store-and-Forward

Answer 20

Reads the entire frame.
Verifies the frame’s integrity with the frame check sequence (FCS).
Forwards the frame to the destination device.