How TCP Works - Duplicate Acknowledgments

You don't have to look far in a Wireshark trace file to find duplicate acknowledgments. This common feature of TCP is an often-misunderstood feature of how the protocol ensures reliable delivery of data from one endpoint to another.

However, when should it worry me? Why do I sometimes see hundreds of duplicate acknowlegments, while in other cases I only see a few? We will dig into those questions and much more in this video. Make sure to download the sample trace file so you can follow along!

Chris Greer is a Network Analyst for Packet Pioneer LLC. He helps organizations of all sizes resolve network performance problems, while training them on how to perform packet-level analysis using Wireshark and other industry tools. Want Wireshark training? Get in touch!