We have a TDI client driver and it talks to a box using TCP. We have noticed
using Ethereal that frequently ACKs are having incorrect checksum that is
being generated by our windowsXP SP1 host driver. We thought it’s a bug in
Ethareal so we installed another porotocol analyser and found the same
result. So, it seemed a bug in our TDI client but we could not find any
reason for this. So, we decided to run some application that uses TCP packet
and found TCP ACKs are having incorrect checksum. Then we ran IE to load
some pages from internet and it still shows incorrect checksum on TCP.
One thing is weird that data is flowing between client & host without any
problem.
The network adapter is ‘Intel(R) PRO/100 M Network Connection’. Currently,
two machines with exact setup from same company show this problem.
Somewhere somethings is not going good.
Please share your thoughts.
Off the bat, it is hard to say, but since you have intel pro/100, you do have an advantage there, basically you can have the IM driver(ndis) and the miniport from the ddk example, do debug build and capture pretty much the whole path if you want …
Wondering if the TCP checksum offload is enabled for the adapter. If it
is perhaps your protocol analyzers get confused?
Vitaly
-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Hakim
Sent: Thursday, June 03, 2004 2:24 PM
To: Windows System Software Devs Interest List
Subject: [ntdev] TCP checksum
We have a TDI client driver and it talks to a box using TCP. We have
noticed using Ethereal that frequently ACKs are having incorrect
checksum that is being generated by our windowsXP SP1 host driver. We
thought it’s a bug in Ethareal so we installed another porotocol
analyser and found the same result. So, it seemed a bug in our TDI
client but we could not find any reason for this. So, we decided to run
some application that uses TCP packet and found TCP ACKs are having
incorrect checksum. Then we ran IE to load some pages from internet and
it still shows incorrect checksum on TCP. One thing is weird that data
is flowing between client & host without any problem. The network
adapter is ‘Intel(R) PRO/100 M Network Connection’. Currently, two
machines with exact setup from same company show this problem.
Somewhere somethings is not going good.
Please share your thoughts.
Is there any way to know if TCP checksum offload is enabled?
Tks,
Hakim
“Vitaly Vatnikov” wrote in message news:xxxxx@ntdev… > Wondering if the TCP checksum offload is enabled for the adapter. If it > is perhaps your protocol analyzers get confused? > > - Vitaly > > -----Original Message----- > From: xxxxx@lists.osr.com > [mailto:xxxxx@lists.osr.com] On Behalf Of Hakim > Sent: Thursday, June 03, 2004 2:24 PM > To: Windows System Software Devs Interest List > Subject: [ntdev] TCP checksum > > > We have a TDI client driver and it talks to a box using TCP. We have > noticed using Ethereal that frequently ACKs are having incorrect > checksum that is being generated by our windowsXP SP1 host driver. We > thought it’s a bug in Ethareal so we installed another porotocol > analyser and found the same result. So, it seemed a bug in our TDI > client but we could not find any reason for this. So, we decided to run > some application that uses TCP packet and found TCP ACKs are having > incorrect checksum. Then we ran IE to load some pages from internet and > it still shows incorrect checksum on TCP. One thing is weird that data > is flowing between client & host without any problem. The network > adapter is ‘Intel(R) PRO/100 M Network Connection’. Currently, two > machines with exact setup from same company show this problem. > > Somewhere somethings is not going good. > Please share your thoughts. > > Thanks, > Hakim > > > > — > Questions? First check the Kernel Driver FAQ at > http://www.osronline.com/article.cfm?id=256 > > You are currently subscribed to ntdev as: xxxxx@relicore.com > To unsubscribe send a blank email to xxxxx@lists.osr.com > >
Very likely it is off, so no offloading if you use the std driver that comes w/the card, but not sure. If I were you, I would have tried to see the checksum w/o the TDI client of yours, most probably something is being cooked somewhere (just suspecisous mind :). BTW, intel has document of their eth controller family, that we discussed about a month ago, and that tells which family has what capabilites. Also you can replace the std. driver with the ebx* driver source in the ddk, I had done once, and if my 2k mem srv’s well chksum off loading is off in the ddk source …
Try adapter properties/configure/advanced in the “Network Connections”.
-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Hakim
Sent: Thursday, June 03, 2004 4:52 PM
To: Windows System Software Devs Interest List
Subject: Re:[ntdev] TCP checksum
Is there any way to know if TCP checksum offload is enabled? Tks, Hakim
“Vitaly Vatnikov” wrote in message news:xxxxx@ntdev… > Wondering if the TCP checksum offload is enabled for the adapter. If > it is perhaps your protocol analyzers get confused? > > - Vitaly > > -----Original Message----- > From: xxxxx@lists.osr.com > [mailto:xxxxx@lists.osr.com] On Behalf Of Hakim > Sent: Thursday, June 03, 2004 2:24 PM > To: Windows System Software Devs Interest List > Subject: [ntdev] TCP checksum > > > We have a TDI client driver and it talks to a box using TCP. We have > noticed using Ethereal that frequently ACKs are having incorrect > checksum that is being generated by our windowsXP SP1 host driver. We > thought it’s a bug in Ethareal so we installed another porotocol > analyser and found the same result. So, it seemed a bug in our TDI > client but we could not find any reason for this. So, we decided to > run some application that uses TCP packet and found TCP ACKs are > having incorrect checksum. Then we ran IE to load some pages from > internet and it still shows incorrect checksum on TCP. One thing is > weird that data is flowing between client & host without any problem. > The network adapter is ‘Intel(R) PRO/100 M Network Connection’. > Currently, two machines with exact setup from same company show this > problem. > > Somewhere somethings is not going good. > Please share your thoughts. > > Thanks, > Hakim > > > > — > Questions? First check the Kernel Driver FAQ at > http://www.osronline.com/article.cfm?id=256 > > You are currently subscribed to ntdev as: xxxxx@relicore.com
“Vitaly Vatnikov” wrote in message news:xxxxx@ntdev… > Try adapter properties/configure/advanced in the “Network Connections”. > > -----Original Message----- > From: xxxxx@lists.osr.com > [mailto:xxxxx@lists.osr.com] On Behalf Of Hakim > Sent: Thursday, June 03, 2004 4:52 PM > To: Windows System Software Devs Interest List > Subject: Re:[ntdev] TCP checksum > > > Is there any way to know if TCP checksum offload is enabled? Tks, Hakim > > “Vitaly Vatnikov” wrote in message > news:xxxxx@ntdev… > > Wondering if the TCP checksum offload is enabled for the adapter. If > > it is perhaps your protocol analyzers get confused? > > > > - Vitaly > > > > -----Original Message----- > > From: xxxxx@lists.osr.com > > [mailto:xxxxx@lists.osr.com] On Behalf Of Hakim > > Sent: Thursday, June 03, 2004 2:24 PM > > To: Windows System Software Devs Interest List > > Subject: [ntdev] TCP checksum > > > > > > We have a TDI client driver and it talks to a box using TCP. We have > > noticed using Ethereal that frequently ACKs are having incorrect > > checksum that is being generated by our windowsXP SP1 host driver. We > > thought it’s a bug in Ethareal so we installed another porotocol > > analyser and found the same result. So, it seemed a bug in our TDI > > client but we could not find any reason for this. So, we decided to > > run some application that uses TCP packet and found TCP ACKs are > > having incorrect checksum. Then we ran IE to load some pages from > > internet and it still shows incorrect checksum on TCP. One thing is > > weird that data is flowing between client & host without any problem. > > The network adapter is ‘Intel(R) PRO/100 M Network Connection’. > > Currently, two machines with exact setup from same company show this > > problem. > > > > Somewhere somethings is not going good. > > Please share your thoughts. > > > > Thanks, > > Hakim > > > > > > > > — > > Questions? First check the Kernel Driver FAQ at > > http://www.osronline.com/article.cfm?id=256 > > > > You are currently subscribed to ntdev as: xxxxx@relicore.com > > > To unsubscribe send a blank email to xxxxx@lists.osr.com > > > > > > > > — > Questions? First check the Kernel Driver FAQ at > http://www.osronline.com/article.cfm?id=256 > > You are currently subscribed to ntdev as: xxxxx@relicore.com > To unsubscribe send a blank email to xxxxx@lists.osr.com > >