Wireshark-users: [Wireshark-users] Need Help! [TCP Previous Segment Lost] message

From: "Johnny Chan" <igloobear@xxxxxxxxx>
Date: Tue, 2 Sep 2008 23:00:21 -0700

Folks,

I have a hand-held device which has a built-in http web server and an
Ethernet port. To turn this device into a true portable system, I
added a wifi bridge and then associate it with our corporate 11b
network.

I am able to ping the hand-held device from my desktop via the WLAN.
However, when I try to browse it using the IE browser, it returns with
a time-out failure. I captured the network traffic using wireshark
from the desktop and found that. Actually the client desktop was able
to initialize the handshake with the web server.

(4291) client to server: TCP src port 3253, dst port 80, [SYN] seq=0
win=64240 len=0 MSS=1460 WS=0
(4292) server to client: TCP src port 80, dst port 3253, [SYN, ACK]
seq=0 ack=1 win=5000 len=0 MSS=1460
(4293) client to server: TCP src port 3253, dst port 80, [ACK] seq=1
ack=1 win=64240 len=0
(4294) client to server: HTTP src port 3253, dst port 80, [GET /
HTTP/1.1] (4295) server to client: TCP src port 80, dst port 3253
[ACK] seq=1
ack=258 win=4775 len=0

Everything is ok until this point, WireShark throw the following two
errors on the next couple lines saying:

(4296) server to client: HTTP [TCP Previous segment lost] Continuation
or non-HTTP traffic src port 80, dst port 3253, seq=2801, next seq
number is 4141, ack=258, length=20

(4297) client to server: TCP [TCP Dup ACK 4294#1] pda-data(3253) >
http [ACK] seq=258 ack=1 win=64240 len=0

This problem is a showstopper. I will very appreciated if someone can
point me the right direction to solve this problem. Attached is the
cap file. Please help!

--igloobear