How Can Wireshark be Used For Network Troubleshooting?
Wireshark is a free, open-source program that is used to analyze network traffic in real time. It was developed in 1997 by Gerald Combs to be a tool for tracking down network problems. Many other developers have contributed to the development of the network analyzer over the years. Originally released under the name “Ethereal”, this tool was re-christened “Wireshark” in 2006. It is a cross-platform application, available for Windows, MacOS, and Ubuntu/Linux.
Wireshark is widely used in the IT industry because it is a powerful tool. To use Wireshark successfully, the user needs a solid knowledge of networking basics, the TCP/IP stack and how to read and interpret the various protocol headers. Wireshark is so widely adopted that knowledge of it is considered a necessary skill for most networking or cybersecurity roles.
The troubleshooting process begins with capturing network traffic into Wireshark. After capturing the desired amount of data, analysis can begin on the log file. Packets moving across the network are captured, logged, and translated from binary into a readable format. By studying these logs, network administrators can identify problems such as dropped packets, latency issues, or even malicious activity. In cases of network troubleshooting, it also helps to get two Wireshark analysis sets — one from a problem machine, and one for comparison from a system that is functioning correctly.
All network traffic can be captured, and it can be difficult to sort through the large amount information. Thousands of network protocols are supported — even ones that are obsolete. Wireshark has built-in tools that can filter and analyze the packets to give insight to suspected network problems quickly. You can create a Capture Filter if you need to capture information on a select protocol. Otherwise, if all traffic is captured, it can be easily sorted using the search bar.
It is possible to display individual packets and see each encapsulated header. They are displayed in the order of the TCP/IP model, with the first layer at the top of the list and the higher level layers following. Each header can then be displayed in detail. The center window displays the header data in a readable format while the bottom window displays the actual binary code. Clicking on a header element in the center window highlights the corresponding code in the bottom window.
In addition to dissecting individual packets, Wireshark allows for analyzing the captured stream of traffic. The Statistics, Conversion tool and the Timing graph are excellent ways to isolate the source of the network problem. Depending on the network protocol you’ve selected, you can drill down to fine details including how much data is being transported (the Bytes option), or highlighting a particular sort of traffic (choose Analyze, then Enabled, then put a check mark on the specific protocols you need). Captured traffic can be saved into separate files and exported into a variety of formats, including .csv. This feature allows for easy documentation of problems as well as sharing of information.
Wireshark’s ability to capture network data, quickly filter it down, and dissect headers is what makes it an essential and powerful tool in troubleshooting networks. Because it is free, it is accessible to professionals and enthusiasts at every level. Because it is open-source, Wireshark will continue to evolve to meet the needs of changing technology as long as there are people willing to contribute to the project.
