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What is probably the world's first productive setup of Samba and Linux clients with SMB3 UNIX Extensions is now up and running at Frankfurt University of Applied Sciences (UAS). Björn Jacke from the SerNet Samba team recently worked with colleagues from the university's IT department to equip the Samba server and connected Linux clients with this new feature for academic purposes.  

Frankfurt UAS had consciously decided not to use dual protocols SMB and NFS. Instead, it now relies on uniform integration with SMB3: Samba's rights and sharing management offers much greater flexibility and easier administration. Without the Unix Extensions, students using Linux workstations were previously restricted in that symlinks or Unix commands such as chmod did not behave as they would on a typical POSIX/Linux system. The operations could not be mapped directly via the SMB protocol. Jacke: “With the new SMB3 UNIX Extensions, Linux clients now work perfectly with SMB mounts from Samba servers, enabling optimal integration without compromise. This makes studying at Frankfurt University even more enjoyable for students.”

Samba 4.22 with SMB3 Unix Extensions

The SMB3 UNIX Extensions feature is available since Samba version 4.22, which was released in April 2025. The topic also dominated this year's sambaXP and can be reviewed in several recordings published on the SAMBA+ YouTube channel.

SerNet has already incorporated some additional features into the current SAMBA+ packages, which will only be part of Samba from version 4.23 onwards in fall 2025.

SerNet: Worldwide partner for Samba projects

Support – remote or directly onsite – is part of the core business of SerNet's Samba team. The team supports companies and organizations in setting up, maintaining, and optimizing Samba infrastructures. The project implementation in Frankfurt shows how practical know-how and technological development come together at the customer's site.

How can we assist you with your Samba environment?

SerNet offers professional assistance with all questions relating to Samba, SMB, and Active Directory – from planning and implementation to ongoing support and development projects. Find out more about our services or contact us directly.

The Samba team at SerNet has completed two key milestones in the ongoing development of SMB over QUIC for Samba. The technology  promises secure, high-performance access to file servers across untrusted networks. These developments are part of the project funded by the Sovereign Tech Agency (STA). The STA supports critical open-source infrastructure to strengthen digital sovereignty and resilience.

Milestone 5.1: Enable QUIC transport in Samba smbd

Samba now supports listening on UDP port 443, enabling a QUIC-based alternative to traditional TCP connections (ports 445 and 139). The groundwork integrates the Linux kernel QUIC driver lxin/quic into Samba's networking logic. This allows Samba to act as a secure “SMB VPN”, ideal for remote work, mobile access, and high-security scenarios.

Milestone 5.2: Enable QUIC testing via socket_wrapper

Testing QUIC implementations without relying on real network interfaces is crucial for fast, automated validation. The team extended socket_wrapper, a tool that emulates network sockets over Unix domain sockets, to simulate QUIC communication using the ngtcp2 userspace library. This approach allows developers to test SMB over QUIC under controlled conditions without kernel dependencies.

With these two milestones, Samba takes a significant step toward full SMB over QUIC support, offering a modern, secure transport layer for the next generation of file services. 

Learn more about the full project and its milestones: https://samba.plus/stf-project

All presentations from sambaXP 2025 are now accessible at YouTube, featuring hours of valuable content and expertise in Samba, open-source technologies and much more. Dive into the latest insights shared at the recent on-site conference, held at Hotel Freizeit In in Göttingen from April 7–8.

One highlight of this year's event was the keynote by Mirko Swillus from the Sovereign Tech Agency (STA). He addressed the necessity and complexities of maintaining digital infrastructure, drawing parallels to physical infrastructure: "Digital infrastructure maintenance resembles the upkeep of roads and bridges. It’s crucial yet often invisible. The Sovereign Tech Agency exists precisely to ensure the sustainability of these fundamental building blocks of our digital society."

Swillus further emphasized international collaboration, stating: "Open source doesn't have borders; it’s a global phenomenon. We must work collectively to sustain these critical resources." And that's exactly what STA does whith its Sovereign Tech Fund. For example, STA currently funds a major Samba project managed by SerNet GmbH. The initiative focuses on enhancing Samba’s security, scalability, and functionality.

Thanks to all speakers and to this year’s sponsors for their support, enabling another successful sambaXP.

Missed the event or want to revisit your favorite sessions? Start exploring the sambaXP 2025 playlist today!

And stay tuned for updates on sambaXP 2026 at sambaxp.org.

The Samba team at SerNet has reached the fourth milestone in the Sovereign Tech Agency-funded project: Regression tests and server adjustments for SMB3 UNIX Extensions have been successfully completed and integrated.

This milestone supports Samba’s goal to deliver local filesystem semantics over SMB – especially for Linux clients, but with future potential for broader adoption (e.g., macOS). The extended SMB3 UNIX feature set improves handling of symbolic links, file permissions, and Unix-specific metadata when accessing files over a network. This closes the gap between traditional Unix behavior and the SMB protocol, enhancing cross-platform compatibility. Extensive regression testing ensures that recent enhancements don't introduce unintended side effects.

With this milestone, Samba moves closer to providing seamless UNIX-like behavior over SMB3. All developments are available via the public Samba repositories. Learn more about the full project and all milestones: https://samba.plus/stf-project

The project and the ongoing development is made possible through funding by the Sovereign Tech Agency, which supports critical open-source infrastructure. The STA’s broader mission is to strengthen digital sovereignty, security, and resilience by enabling long-term development and maintenance of critical technologies. SerNet has secured the funding for Samba and manages the milestones.

The Samba team at SerNet GmbH has reached the second milestone (2/17) in the Sovereign Tech Agency.-funded project to enhance Samba’s functionality and interoperability. This milestone focuses on introducing SMB3 Directory Leases, a feature designed to improve performance and efficiency when working with shared files and folders. With this implementation, clients can establish leases on directories, enabling caching of directory contents, reducing network overhead for directory metadata operations, and enhanced responsiveness in shared environments.

The development team conducted in-depth research and testing to ensure compatibility with Microsoft's SMB3 implementation. This led to the identification of multiple bugs and deficiencies in Samba. As a result, the team thoroughly investigated the current SMB2 Leases implementation in Samba, fixing all bugs and enhancing Samba's continuous integration testing framework with rigorous testing.

This highlights the team’s commitment to maintaining seamless interoperability between Samba and Microsoft environments, a cornerstone of the project’s objectives.

The work on this milestone has been published and will be available in the public Samba repositories:

• Implementation of SMB3 Directory Leases

This achievement, like others in the project, ensures that the open-source community and organizations relying on Samba benefit from new features and robust cross-platform compatibility. The ongoing funding secured by SerNet and assigned by the Sovereign Tech Agency (STA, formerly known as Sovereign Tech Fund) enables these advancements, underscoring the collaborative effort behind the project.

For further information about the project, visit https://samba.plus/stf-project. The project is a long-term initiative aimed at strengthening Samba’s role as a critical open-source software for file sharing, interoperability, and identity access management. Over the course of 18 months, the project will complete 17 milestones to enhance Samba’s security, scalability, and functionality. Each milestone’s results are made publicly available, ensuring that the wider open-source community and IT infrastructures worldwide can benefit.