TCP/IP Network Traffic Analysis with Wireshark Training Course

Day 1

Overview of Network Analysis

1. Essentials of the OSI Reference Model and TCP/IP networks.
2. Methodologies and tools for troubleshooting.
3. Introduction to Wireshark
4. What is Wireshark? Portable Wireshark. Resources.
5. Wireshark GUI structure: Panes (Packet List, Details, Packet Bytes), Status Bar, ... .
6. Architecture and processing flow. What and why cannot be seen with Wireshark?
7. Supported protocols. Dissectors.
8. Preferences and configurations; global and profile specific.
9. Time values.
10. Lab exercises.

Day 2

Capture traffic

1. Things to consider before start.
2. Promiscuous mode.
3. Capture filters.
4. Automatic stop criteria.
5. Remote capture.
6. Lab exercises.

Traffic analysis: tools and approaches

1. Analysis checklist.
2. Using features: name resolution, colorization, marking, ignoring, commenting, using time references, time shifts, etc.
3. Understanding Expert System.
4. Accessing options through Right-Click functionality.
5. Interpretation (reference patterns), OS/driver Offload features impact.
6. Saving results.
7. Lab exercises and case studies.

Day 3

Traffic analysis: tools and approaches (cont.)

1. Filtering traffic: Display filters (preparing "in-flight" filters, macros), following stream.
2. Quantitative analysis.
   1. Basic predefined descriptive statistics and summaries: Capture Properties, Protocol Hierarchy, Conversations, Endpoints, Packets Lengths, IP-specific.
   2. Protocol specific analysis (e.g.: TCP Stream Graphs).
   3. Advanced custom statistics with I/O Graph.
   4. Flow visualization.

Day 4

Traffic analysis: protocols

1. Data-Link Layer: Ethernet II.
2. Network Layer: IPv4.
3. Transport Layer: TCP, UDP.
   1. Packet loss and recovery.
   2. Previous segment lost and Out-of-Order Segments events.
   3. Duplicate ACKs and Fast Retransmissions.
   4. TCP Retransmissions.
   5. Zero Window, Window changes and other window problems.
4. Application layer: HTTP, FTP.
5. Lab exercises and case studies.

Day 5

Traffic analysis: common issues in network performance assessment

1. Cause of performance problems.
2. Packet loss.
3. Bandwidth issues. Layered approach to measurement.
4. Latency: assessing end to end latency, visualization.
5. Lab exercises.
6. (Wireshark) command-line tools:
   1. tshark (terminal-based wireshark) / dumpcap / rawshark, tcpdump
   2. editcap, mergecap, capinfos, text2pcap.

Advanced topics

1. Advanced filters, grouped iostats.
2. Summary and Q&A.