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Storage at Microsoft
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SMB Signing and Guest Authentication

NedPyle's avatar
NedPyle
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Jun 13, 2023
Heya folks, Ned here again. We recently made SMB signing the default in Windows Insider and Windows Server Insider builds. In doing so, we were quickly reminded of a consequence from an old unsafe SM...
Updated Apr 09, 2024
Version 5.0
NedPyle's avatar
NedPyle
Icon for Microsoft rankMicrosoft
Apr 04, 2024

We are turning signing on by default in Windows Server 2025 and Windows 11 vNext:

 

SMB signing required by default in Windows Insider - Microsoft Community Hub

Next-generation SMB file services | Windows Server Summit 2024 (microsoft.com)

 

It should not be turned off on domain controllers either. Also, all of your Windows 10/Windows Server 2016 and later machines have still been requiring SMB signing from your domain controllers when connecting to the SYSVOL and NETLOGON shares, through UNC Hardening defaults.

 

SMB signing will prevent a variety of attacks and should be required unless you have specific reasons not to require it, such as certain throughput/latency requirements for specific workloads.