MySQL Bugs: #62368: TCP Checksum incorrect

Bug #62368	TCP Checksum incorrect
Submitted:	7 Sep 2011 7:07	Modified:	7 Nov 2011 15:36
Reporter:	Bo Biene	Email Updates:
Status:	No Feedback	Impact on me:	None
Category:	Connector / NET	Severity:	S1 (Critical)
Version:	6.4.3	OS:	Windows
Assigned to:	Assigned Account	CPU Architecture:	Any
Tags:	TCP CHECKSUM

Description:
Connection to a remote MySql Server (ver. 5.1).
Captured to tcp-traffic via WireShark.

I have tried a connection to a mysql host in a diffrent network location (subnet) wich failed. After analysis with wireshark i found out that the tcp-checksum seems to be inocorrect. The router seems not to transmit a package with incorrect checksum.

Connection from the same subnet is working fine with the same connector driver.

Connection from diffrent subnet is working with mysql-admin/query-browser.
Connection from diffrent subnet is working with an older mysql-driver (5.1.4.0).

TCP sniff working and not working is attached.

How to repeat:
Capture traffic on tcp port 3306 with wireshark while a connection is made with mysql-driver .NET ver. 6.4.3.

TCP sniff - connection working (same sub)

Attachment: working.txt (text/plain), 19.74 KiB.

Thanks for your bug report Bo Biene,

MySql Connector doesn't calculate TCP cheksums, that happens between the System.Net.Sockets & NIC layers.
Can you confirm if your NIC is using TCP offloading, as described in the following article: http://wiki.wireshark.org/CaptureSetup/Offloading?

Thanks.

No feedback was provided for this bug for over a month, so it is
being suspended automatically. If you are able to provide the
information that was originally requested, please do so and change
the status of the bug back to "Open".