I can connect from laptop to Omron PLC CJ1M using TCP Fins Driver. I cannot connect however when I use the company network. Wireshark shows SACK_PERM = 1.
The parameters of the local network are:
Any idea which parameter must be changed, since obviously it is not Omron TCP driver issue.

Thank you!

At the risk of being wrong and surprised again… I doubt this has anything to do with TCP selective ack being enabled or not. You probably just don’t have a route to the PLC on your company network or something.

That said, feel free to f around in your registry: Description of Windows TCP features - Windows Server | Microsoft Docs

Hi, Kevin, thank you for your prompt reply. I doubt too the issue has to do anything with SACK. In any case, I would not like to play around with the resisters on the server where Ignition and Kepware are installed, this is just in case I cannot figure out other solution. I was thinking what would help me is command netsh run on a computer where Omron TCP driver is in use, or Powershell TCP parameters list. That would be of real help…

It took me more time but the issue is solved. Not network problem.
Gateway IP address need to be added in ETN21 card settings:

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