Win7 Client not sending a PSH, ACK

asked 2019-12-23 20:21:41 +0000

szeWS gravatar image

We have a Win7 client communication with a Win10 server(virtual machine). The Win10 server is not a Windows Server but rather a Win10 VM acting as a server.

The Win7 client communicates fine with a Win7 server(physical machine). We see the protocol sequence exhibiting correct behavior. SYN SYN, ACK ACK PSH,ACK ACK, PSH,ACK

In the case of the Win7 client communicating with Win10 server(virtual machine). We see the protocol sequence exhibiting incorrect behavior. SYN SYN,ACK ACK, PSH,ACK ACK <expecting a="" psh,ack=""> here - albeit not receiving one - hence causing test failure.

We have removed firewall rules on both client and server machines and same symptoms persist. Client and server are on different subnets.

Question: What might cause the client not respond with a PSH, ACK? All works fine when it's Win7-Win7 but fails when it's Win7-Win10.


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Can you share a capture file with the issue on the Win7-Win10 connection? Share it on a public site such as Google Drive, DropBox etc. and post a link to it back here.

grahamb gravatar imagegrahamb ( 2019-12-24 10:01:09 +0000 )edit

Looks like symptoms a bit different now. For Win10(fail run), appears no further data after the line "SSL 96 Continuation Data". For Win7(successful run), there's data after "SSL 96 Continuation Data" packet. Is there another way to send the captured file(s)? Google Drive appears to "hang" when I try to upload file(s). Stays at "Starting Upload..." yet no files are uploaded. Filesize is 1.8 MB

Confrmed: Symptoms still the same - missing PSH,ACK on Win10. Was using WireShark incorrectly. File is still trying to upload.

szeWS gravatar imageszeWS ( 2019-12-30 14:43:42 +0000 )edit