Basic Network Troubleshooting Using Wireshark

Description
The purpose of the course is to provide the participant with basic knowledge of the Wireshark protocol analyzer. The course focuses on deep understanding of the tool, as the basics for using it for network troubleshooting. The course starts with packet capturing, capture and display filters, statistical features and the basics of the expert system. By the end of the course the participant will be able to perform basic troubleshooting in small to medium size networks. The course is based on theory, class exercise and labs.

Objectives
By the end of the course, the participant will be able to:

• Perform data capture
• Design and implement troubleshooting techniques
• Set up various display and capture filters
• Use statistical tools and software to detect network failures
• Use the software I/O graphical tools
• The Expert system basics
• Use the tools learned for troubleshooting TCP/IP networks

 

Topics

• Using Wireshark for capturing and analyzing network syndromes
• Display and capture filters
• Wireshark statistical tools – packet statistics, IO graphs, TCP stream graphs and more
• The Expert system and how to use it for network analysis

Target Audience
R&D, engineering and technical Support, IT and communications managers

Prerequisites
Basic knowledge in networking and the TCP/IP protocol stack. The participants should come with Laptops with Wireshark software (free download from the site - Www.wireshark.org)

Duration
2 Days

Outline

• Introduction to network troubleshooting
  • What is network troubleshooting
  • Troubleshooting tools
  • Troubleshooting methodologies
• Introduction to Wireshark
  • How Wireshark Works
  • Capturing Packets,
  • What are capture and display filters
  • Configuring Global Preferences
  • Navigation and Colorization Techniques
  • Using Time Values and Summaries
  • Examining Basic Trace File Statistics
  • Save, Export and Print
• Capture and Display Filters
  • Capture filters – basics and filter language
  • Display filters – basics and filter language
  • Useful filters
  • Case studies
  • Using Time Values and Summaries
  • Use the default time column setting and precision
  • Use time between packets
  • Set a time reference and view capture times
  • Troubleshooting timing problems
  • Case studies
• Using Statistics Tools
  • Create I/O graphs
  • Create TCP Time-Sequence graphs
  • Analyze flow graphs
  • Evaluate service response times
  • Create Round-Trip-Time graphs
  • Analyze TCP/IP flows
  • Analyze applications flows
• The Expert System Basics
  • Normal and un-normal Network Communications
  • Causes of Performance Problems
  • Packet Losses, Ack to longs and Retransmissions
  • Case Studies
• TCP performance issues
  • High Latency
  • Packet Loss
  • Flooded Network