📢 Windows 11 Build 25992 adds several changes to SMB Protocol

What's new and improved in Windows 11 Build 25992

One of the significant changes in Windows 11 Build 25992 revolves around the Server Message Block (SMB) protocol. Microsoft is taking network security to the next level with the following modifications:

SMB Firewall Rule Changes

Previously, creating an SMB share would automatically configure the firewall to enable rules in the "File and Printer Sharing" group, which allowed traffic on ports 137-139, among others. With the new update, Windows introduces the "File and Printer Sharing (Restrictive)" group, which omits inbound NetBIOS ports 137-139. This change aims to enhance network security by reducing potential vulnerabilities. Administrators still have the flexibility to configure the old firewall group if needed.

SMB NTLM Blocking Exception List

This update extends the SMB NTLM blocking feature introduced earlier. It now allows administrators to create exception lists for NTLM usage. This means you can set up a general block on NTLM usage while permitting specific servers to use NTLM for authentication, particularly in cases where Kerberos is not supported.

SMB Alternative Client and Server Ports

The SMB client in Windows 11 now supports connecting to an SMB server using alternative network ports like TCP, QUIC, or RDMA, providing more flexibility. In the past, SMB was limited to default ports, but now it can be configured to work with different port options. This change enables greater versatility and customization in SMB connections.

SMB Over QUIC Client Access Control Certificate Changes

SMB over QUIC client access control has been enhanced to support certificates with subject alternative names. This means that multiple endpoint names are now supported, making it easier to manage and secure your network connections. You can now utilize a Microsoft AD Certificate Authority and eliminate the need for self-signed test certificates.

Other Improvements and Fixes in Windows 11 Build 25992

In this build, Windows 11 brings several noteworthy changes and improvements:

• Microsoft has improved the performance of opening large .zip files in File Explorer. Users will also be pleased to know that support for creating 7-zip and TAR archives is now included alongside ZIP.
• Windows 11 introduces suggestions in Snap Layouts to help users quickly organize multiple app windows. When hovering over the Minimize or Maximize button on an app or using WIN + Z, you'll see app icons displayed in various layout options, making it easier to choose the best layout that suits your needs.
• Blank options on the Personalization and Privacy & Security settings pages have been fixed, preventing crashes when clicked.
• Context menus invoked via touch or pen on the desktop no longer draw off the screen.
• Issues with the Settings Home prompt to sign into your Microsoft account have been resolved.
• Quick Settings crashes and WIN + A not working have been fixed.
• Taskbar icons will no longer disappear after switching desktops.

End Notes

Windows 11 Build 25992 brings many improvements to SMB protocol, enhances network security, and offers a more streamlined user experience. With the added support for different archive formats and the convenience of Snap Layout suggestions, this build aims to improve your Windows 11 experience. As Microsoft continues to refine and enhance its operating system, Windows Insiders in the Canary Channel can look forward to even more exciting updates in the future.