Ravindra BagaleCourses & study guides

24. Traffic Sniffing and Analysis

24.3 Wireshark: Reading Traffic in a GUI

In short: Wireshark is the standard graphical packet analyser.

Wireshark is the standard graphical packet analyser. Start it, pick an interface, and watch packets arrive; or open a .pcap from tcpdump.

wireshark            # GUI (ships with Kali)
# to capture without root in the GUI, add your user to the wireshark group once:
sudo usermod -aG wireshark $USER      # then log out and back in

The window has three parts: the packet list (one row per packet), the packet details (protocol layers you can expand – Ethernet, IP, TCP, HTTP), and the packet bytes (raw hex). Colours group protocols; the columns show source, destination, protocol and info.

Ravindra Bagale's Tip

When they open Wireshark and see thousands of packets, students panic. Don't worry – nobody reads every packet. Apply a filter (next section) and look only at what you need. Learning Wireshark means learning filters.

Lab

Open web.pcap from 24.2 in Wireshark. Expand one HTTP packet and identify the four layers (Ethernet, IP, TCP, HTTP). Note the source and destination IP and the TCP ports.