Advanced Network Understanding with Wireshark

When an outage, slow application, or suspicious connection hits, many IT teams rely on guesswork because few people can read what is actually crossing the wire. This intermediate course helps close that gap. It builds packet-level fluency across IPv4, IPv6, TCP, UDP, ICMP, DNS, and Microsoft protocols such as SMB and RPC, then layers on Wireshark display filters, logical operators, and BPF filtering.

Role fit: Assign it to network engineers, SOC analysts, and support or infrastructure staff who already know basic networking and the OSI model. The instructor directs newer staff to foundational courses first. The course is part three of an ongoing cybersecurity and pen testing series, so security-focused teams get a natural progression.

Time investment: Plan on about 10.5 hours per learner across 12 skills of roughly 50 minutes each. Team Leads can schedule one skill per week without pulling people off operations.

Risk and operations framing: The course explains how payload-level analysis supports incident reconstruction, troubleshooting broken communications, and building IDS/IPS detections. It also notes that older Windows systems may still run legacy protocols in production environments.

Change-management notes: Learners capture live traffic in promiscuous mode on Windows and Ubuntu and work in virtual machines, including a domain controller running DNS. Confirm that your capture and monitoring policies allow sanctioned lab work before learners start. Supplemental PDFs with packet headers and hex, binary, and decimal conversion tables are included.

CBT Nuggets Playlists let Training Managers pair this course with related Wireshark and pen testing content. Team Reporting gives IT Directors visibility into each learner's progress.

IT teams complete this training to move from guessing at network problems to proving what is happening on the wire. The course works through live captures, display filters, and packet-header breakdowns across IPv4, IPv6, TCP, UDP, ICMP, DNS, and Microsoft protocols, so analysts can tie raw packets to real incidents.

• Faster root-cause analysis on connectivity issues. Your team learns to read TCP three-way handshakes, trace ICMP tracert responses hop by hop, and see why a route behaves unexpectedly. Outages can then be resolved with evidence instead of trial and error.
• Clearer DNS troubleshooting. Practitioners point queries at a specific DNS server, such as a domain controller, and inspect the resulting traffic to confirm whether name resolution is where the failure lives.
• Sharper threat detection in Windows-heavy environments. Coverage of SMB, RPC, and other Microsoft protocols, including legacy systems still in production, helps SOC analysts spot traffic that should not be there and piece together an incident from payload data.
• Filters that carry over to IDS/IPS work. Logical operators in display filters and BPF syntax, such as flagging packets with the TCP urgent flag set, give your team search logic it can reuse in tools like Security Onion, Snort, or Splunk to surface crafted or suspicious packets.

Supplemental reference material, including packet-header charts and hex/binary/decimal conversion tables, gives your team a shared baseline it can keep using after the course.

Knowledge

• How packets are built across the OSI model and TCP/IP stack, from Ethernet II through IPv4/IPv6 headers to the transport layer and application payload
• How TCP delivers reliable communication through the three-way handshake and its flags, and how UDP trades reliability for speed in uses like multicast streaming
• How ICMP supports diagnostics such as traceroute, and why hop responses can vary when traffic takes different routes
• How DNS queries resolve against a specific server, such as a domain controller running DNS, and how Layer 5–7 protocols like SMB fit into the packet
• Which Microsoft protocols, including RPC, run in Windows networks, and how the Windows version affects which protocols are in use
• How Wireshark display filters, logical operators (and/or), and BPF syntax relate to detection logic in IDS/IPS tools like Snort and Security Onion

Ability

• Capture live traffic in promiscuous mode on Windows and Ubuntu systems with Wireshark and tcpdump
• Isolate TCP, UDP, ICMP, and DNS traffic in a capture and read their header fields, including hex-to-binary-to-decimal conversion
• Build and combine display filters on live captures to quickly narrow large captures to the traffic that matters
• Trace the three-way handshake and spot flags that warrant a closer look, such as the URG flag, which can point to a crafted packet or a network fault
• Analyze Windows protocol payloads to reconstruct an incident, diagnose a broken communication path, or inform IDS/IPS rule building
• Apply advanced filtering techniques to earlier protocol analysis to find traffic that should or should not be on the network