Wireshark-users: Re: [Wireshark-users] Help: Confuse about TCP Previous Segment Lost
TCP Previous Segment Lost means that there was a hole in the conversation. As you read through the TCP conversation, you'll see that there is at least one segment missing from the capture, either because it was dropped somewhere on the network, or dropped during capture (because pcap or whatever was doing the capture couldn't keep up, possibly). This message has nothing to do with an individual segment being truncated or corrupted (which would be much more peculiar and you'd see other error messages).
