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!
