Wireshark-users: [Wireshark-users] Strangest thing ever !!! Captures only TCP SYN handshake negotiation and not any data ?!?

From: "Free Prefix" <free.prefix@xxxxxxxxx>
Date: Thu, 3 May 2007 13:46:22 +0200

Hello All,

Recently I have encountered a very strange phenomenon happens on one
of our new servers.

Server details:
IBM XSeries_3550, Intel Xeon CPU 5130 @ 2 ghz
Network Card: Broadcom BCM5708C NetXtreme II GigE (NDIS VBD Client)
WinPCap 4
Wireshark: 0.99.5

When sniffing network traffic with Wireshark, I can see only the TCP
3-way handshake captured but not the traffic itself afterwards. This
happens using any winsock application including Internet explorer and
such , see attached: Browsing_through_iexplore.cap
The most bizarre thing is that if I am doing "telnet" to the same web
server and passing data through the connection I can indeed see the
traffic, see: Browsing_through_telnet.cap

I thought at first it could be a running Antivirus application or such
that at some level captures the network traffic to analyze viruses
before it reaches winpcap but I doubt it because no such application
exist on the server.

I think the problem got more to do with WinPCap but still if someone
has a clue that would be great :)

Any thoughts around this ?

Attachment: Browsing_through_iexplore.cap
Description: Binary data

Attachment: Browsing_through_telnet.cap
Description: Binary data