Forum Discussion
W10-1903 UNC path failing 0x80070043
- Jun 13, 2019
Hi everyone. We got access to the Dell KB and see the issue in Dell/EMCs 'Unity' CIFS implementation.
From the DELL EMC KB attached to thread (below), the Unity SMB Server implementation is failing on the "SMB2_NETNAME_CONTEXT" and "SMB2_COMPRESSION_CAPABILITIES" we added in 1903. These were changes designed to add some new capabilities to SMB; we make some variant of these at most OS releases. If an SMB/CIFS server doesn't recognize capabilities, it should ignore them, not fail. Otherwise Dell would have to update their SMB implementation every time we released a new SMB capability that didn't also include a protocol dialect revision (like "SMB 3.1.2"), forever and ever.
Error Messages in the Unity c4_safe_ktrace.log:
sade:SMB: 3:[nas_serverx] Unrecognized SMB2 negotiate context type 0003
sade:SMB: 3:[nas_serverx] Unrecognized SMB2 negotiate context type 0003SMB client sends the compression context before the netname context, so the server encounters the compression context first. The Unity server would probably encounter the same problem with the netname context. Instead of failing when their SMB Server version doesn't support more advanced capabilities, it should be ignoring those capabilities. This is what Windows and other 3rd party SMB products do.
kurgan thanks for opening this techcommunity item, I'm sorry I didn't see it until now.
Ned Pyle | Principal Program Manager, MS | @nerdpyle on twitter
Okay followed up on it, our IT department has disabled smb3 for now to fix it.
- NedPyleJun 13, 2019Microsoft
kurgan I am the owner of SMB. I have not received any reports of this issue from Dell, nor any similar symptoms from other customers using non-Dell products. The symptoms, workaround, & lack of other vendor reports suggests an issue with Dell's specific implementation of SMB 3.1.1.
Regardless, I am not going to punt this. If you have opened a support case on this issue with Microsoft, please private message me the SR #. I am following up with our contacts at Dell to find out if they've spoken to us about this.
Whenever an OEM says it's an MS problem and asks you to uninstall critical security updates and stop using the safest network protocols, I highly recommend you immediately open a Support Case with MS and that vendor and force that vendor to prove it, before de-securing your systems.
Ned Pyle | Principal Program Manager, MS | @nerdpyle on twitter