Loopback connectivity not working (client/server communicati

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Nani2222
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Joined: 03 Dec 2013, 08:25

Loopback connectivity not working (client/server communicati

Post by Nani2222 »

We are facing a scenario where OPC UA client/server communication is not success when we are using the local host.

Scenario:
We are using “Prosys Java sdk in Server implementation” and “Unified automation’s .net sdk in Client implementation” .OPC server is binded to only localhost and loop back ip address (127.0.0.1).When PC is in network Client server communication is happening. But when the PC is not in network client to server connectivity is not happening and UA’s Client is showing some error message . Can you please help me out on this issue to make the client server communication even when the PC is not in network?


FYI : This problem is not seen when i try to connect to server using Prosys java sdk client.

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Support Team
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Joined: 18 Mar 2011, 15:09

Re: Loopback connectivity not working (client/server communi

Post by Support Team »

Hello Nani,

the problem occurs on Windows OS from Vista/Win7 upwards. The default behavior in name resolution on loopback address was changed, when there is no network detected by the OS. On old Windows XP it all works fine, as it can still resolve the name using the good old etc\hosts file.
Anyway, we have fixed the issue in the SDK. Please test this issue with latest .NET SDK version V2.2.2 again and report back here. The problem should be solved.

Best Regards
Support Team

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