Free CCNA | Wireshark Demo (TCP/UDP) | Day 30 Lab | CCNA 200-301 Complete Course

Introduction

This tutorial provides a step-by-step guide on using Wireshark to analyze TCP and UDP traffic as demonstrated in Jeremy's IT Lab CCNA 200-301 course. Understanding how to capture and analyze network packets is crucial for aspiring network professionals, making this lab particularly relevant for CCNA students.

Step 1: Setting Up Wireshark

1. Download and Install Wireshark

   • Visit the Wireshark website.
   • Download the version compatible with your operating system.
   • Follow the installation instructions provided.

2. Start Wireshark

   • Launch the Wireshark application.
   • Select the network interface you want to monitor (e.g., Ethernet, Wi-Fi).

3. Begin Capturing Traffic

   • Click on the selected interface to start capturing packets.
   • Observe the live capture of network traffic in real-time.

Step 2: Analyzing TCP Traffic

1. Filter TCP Packets

   • In the filter bar at the top, type tcp and press Enter.
   • This will display only TCP packets captured.

2. Understanding the TCP Three-Way Handshake

   • Look for a TCP SYN message. This is the first step of the handshake.
   • Identify the SYN-ACK response from the server.
   • Finally, find the ACK message that completes the handshake.

3. Inspecting TCP Details

   • Click on any TCP packet to view detailed information.
   • Expand the sections in the packet details pane to examine fields like Source Port, Destination Port, Sequence Number, and Acknowledgment Number.

Step 3: Analyzing UDP Traffic

1. Filter UDP Packets

   • Clear the previous filter and type udp in the filter bar.
   • Press Enter to display only UDP packets.

2. Understanding UDP Characteristics

   • Notice that UDP does not establish a connection like TCP; packets may arrive out of order.
   • Analyze the Source Port and Destination Port fields in the packet details.

3. Inspecting UDP Details

   • Click on any UDP packet to view its details.
   • Examine the length and checksum fields for further insights.

Step 4: Conducting Practical Exercises

1. Capture Traffic During a Specific Application Use

   • Open an application that uses TCP or UDP (e.g., a web browser for TCP or a streaming service for UDP).
   • Capture the packets while using the application to see real-world traffic.

2. Analyze Your Findings

   • Compare the captured packets to the expected behavior of TCP and UDP.
   • Note any anomalies or unexpected packet behaviors.

3. Homework Assignment

   • Reflect on the differences between TCP and UDP traffic observed in your analysis.
   • Prepare to discuss these findings in your next study session.

Conclusion

In this tutorial, you learned how to set up Wireshark, capture, and analyze both TCP and UDP traffic. Understanding these protocols is essential for network troubleshooting and optimization. As you continue your CCNA studies, practice capturing and analyzing different types of traffic to deepen your comprehension and skills. For further learning, consider exploring additional resources or labs related to network protocols.