Microsoft continues its campaign to improve Windows security with latest Insider build
SMB signing in is now required by default for all connections when running the latest Insider build of Windows 11.
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What you need to know
Microsoft wrapped up the week with one more Insider build of Windows 11. Those in the Canary Channel can now download Windows 11 Insider Preview Build 25381. The update includes a change to Server Message Block (SMB). The protocol now requires signing in by default on all connections.
Our Windows expert Mauro Huculak defined SMB in his piece onhow to access files on network devices using SMBv1 on Windows 10:“Server Message Block (SMB) is a networking file share protocol included inWindows 10that provides the ability to read and write files and perform other service requests to network devices. Usually, you’ll be using SMB to connect to devices that don’t run Windows, such as a router with file sharing capabilities, Network-Attached Storage (NAS), or other computers running Linux.”
Here are all of the changes in the latest Insider build, asoutlined by Microsoft:
Build Build 25381: What’s new
SMB signing requirement changes
Beginning with Windows 11 Insider Preview Build 25381 Enterprise editions, SMB signing is now required by default for all connections. This changes legacy behavior, where Windows 10 and 11 required SMB signing by default only when connecting to shares namedSYSVOL and NETLOGONand where Active Directorydomain controllersrequired SMB signing when any client connected to them. This is part of a campaign to improve the security of Windows and Windows Server for the modern landscape.
All versions of Windows and Windows Server support SMB signing. But a third-party might disable or not support it. If you attempt to connect to a remote share on a third-party SMB server that that does not allow SMB signing, you may receive the one of following error messages:
You can follow the steps inMicrosoft’s blog postto resolve the issues above.
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Build Build 25381: Changes and Improvements
General
Sean Endicott is a tech journalist at Windows Central, specializing in Windows, Microsoft software, AI, and PCs. He’s covered major launches, from Windows 10 and 11 to the rise of AI tools like ChatGPT. Sean’s journey began with the Lumia 740, leading to strong ties with app developers. Outside writing, he coaches American football, utilizing Microsoft services to manage his team. He studied broadcast journalism at Nottingham Trent University and is active on X @SeanEndicott_ and Threads @sean_endicott_.
