Troubleshooting Performance Issues

Question 1

What occurs when two hosts on the network transmit at the same time?

Answer 1

Collisions occur when two hosts on the network transmit at the same time, causing their signals to combine and become unreadable.

Question 2

What is a Collision Domain?

Answer 2

A Collision Domain is a network segment where simultaneous data transmissions can collide.

Question 3

How can collisions be detected in a network?

Answer 3

Collisions can be detected by monitoring network performance and using the ‘show interface’ command on network devices.

Question 4

What are Late Collisions?

Answer 4

Late Collisions are detected after 5.12 microseconds and are normal in hub-based networks but should not occur in switch-based networks.

Question 5

What are common causes of Late Collisions?

Answer 5

• Incorrect cables
• Bad network interface cards
• Too many hubs

Question 6

What are Excess Collisions?

Answer 6

Excess Collisions occur when a device exceeds the limit for retransmitting after a collision.

Question 7

What command displays the number of excessive collisions?

Answer 7

The command ‘show controller ethernet’ displays the exact number of excessive collisions.

Question 8

What causes Broadcast Storms?

Answer 8

Broadcast Storms occur when a network is overwhelmed by continuous multicast or broadcast traffic.

Question 9

What are the Layer 2 and Layer 3 addresses associated with Broadcasts?

Answer 9

• Layer 2 – FF:FF:FF:FF:FF:FF
• Layer 3 – 255.255.255.255

Question 10

What is a Broadcast Domain?

Answer 10

A Broadcast Domain is a logical division of a computer network where all nodes can reach each other by broadcast at the data link layer.

Question 11

What are main causes of Broadcast Storms?

Answer 11

• Too large singular broadcast domain
• Large volume of DHCP requests
• Loops created in the switching environment

Question 12

How can Broadcast Storms be prevented?

Answer 12

• Break up large broadcast domains using Layer 3 devices
• Limit MAC addresses per port
• Set up loop prevention mechanisms like Bridge Protocol Data Units (BPDUs)

Question 13

What is VoIP?

Answer 13

Voice Over Internet Protocol (VoIP) is a set of protocols for sending streaming voice and video in real-time over the internet.

Question 14

What impact does latency have on VoIP?

Answer 14

Latency over 100-200ms can cause noticeable audio issues, such as echoes.

Question 15

What is Jitter?

Answer 15

Jitter is the variation in delay over time, measured by sampling the elapsed time between packet arrivals.

Question 16

What is Quality of Service (QoS)?

Answer 16

Quality of Service (QoS) is a mechanism to prioritize certain traffic over others.

Question 17

What are common causes of Packet Loss?

Answer 17

• Network Congestion
• Faulty Router Configurations
• Bad Cables
• Hardware Failures

Question 18

What tools can be used to troubleshoot Packet Loss?

Answer 18

• Ping
• Traceroute

Question 19

What are the most common causes of network performance issues?

Answer 19

• High CPU Usage
• High Bandwidth Usage
• Poor Physical Connectivity
• Malfunctioning Network
• DNS Problems

Question 20

What is an Optical Link Budget?

Answer 20

An Optical Link Budget is a calculation of anticipated losses along the length of a fiber optic connection.

Question 21

What are common issues with Digital Certificates?

Answer 21

• Not signed by a trusted authority
• Expired
• Missing

Question 22

What does BYOD stand for?

Answer 22

BYOD stands for Bring Your Own Device.

Question 23

What are challenges associated with BYOD?

Answer 23

• Support Challenges
• Security Concerns

Question 24

What should be done to resolve hardware failures?

Answer 24

Replace failed components or devices and ensure backups and spare parts availability.