Reading data from a network sniffer

We downloaded a Windows network sniffer program as you suggested to troubleshoot a network slowdown. Now what? We see the results, but without some idea of what we’re looking for it’s like reading a foreign language.

We downloaded a Windows network sniffer program  as suggested in your Aug. 28, 2000 column to troubleshoot a network slowdown. Now what? We see the results, but without some idea of what we’re looking for it’s like reading a foreign language.

After selecting the default network adapter from the setup menu, go to the Captures menu and choose Begin. Click the Start button in the pop-up dialog.

Let the capture continue until you observe the network symptoms you are troubleshooting, then click the Stop button. The program displays a spreadsheet with columns for destination and source media access control addresses, IP addresses, and a summary identifying TCP/User Datagram Protocol (UDP) port numbers and protocol information.

Click the IP address column labeled Network to sort the data by IP connection. Look for the IP addresses of the machines giving you trouble. Scan through the summaries, looking for sudden changes such as unanswered or repeated requests that coincide with the communications slowdown.

Experiment with the Advanced Filter settings in the startup dialog to narrow the search for subsequent captures.