90 DAYS LEFT: Windows Server 2016 End of Life January 2027 – Plan Your AD CS Migration Now

Heads up, fellow Windows Server administrators! There are now just THREE MONTHS remaining before Windows Server 2016 reaches end of support, so now is the time to finalize any migrations for workloads hosted on this platform. Mainstream support ended on January 11, 2022, and Windows Server 2016 has since remained in extended support. However, extended support ends on January 12, 2027. After that date, Microsoft will no longer provide security updates or technical support, increasing the risk of running production workloads due to exposure to newly discovered vulnerabilities and exploits.

Active Directory Certificate Services

Many organizations are still running critical infrastructure on Windows Server 2016. Administrators often delay upgrading Microsoft Active Directory Certificate Services (AD CS) due to its complexity. However, a well-planned AD CS migration not only reduces risk but also provides an opportunity to modernize cryptography, certificate templates, and operational practices.

Certificate Authorities

Administrators must carefully migrate Certificate Authorities (CAs) running on Windows Server 2016 to minimize downtime. In environments where ongoing CA maintenance has been limited, migrating the CA database can be especially challenging. If the CA is installed on a domain controller, now is a good time to consider separating these services to ensure reliable operation. Also, it’s a good idea to evaluate the CA’s configuration and security posture during migration to enhance security and improve service resilience.

NDES Servers

Microsoft Network Device Enrollment Services (NDES) servers, commonly deployed to facilitate certificate enrollment via Microsoft Intune, pose a unique challenge during migration. Unfortunately, configuring NDES is exceedingly complex and error-prone. NDES relies on a delicate combination of specialized IIS configuration, AD service accounts, custom certificate templates, and CA permissions, making even minor changes risky without proper planning. Not surprisingly, administrators are often hesitant to touch these systems as they are notoriously difficult to troubleshoot when problems arise.

Pro Tip: We spend an entire day covering NDES configuration in the Mastering Enterprise PKI Certificates with Microsoft Intune training course. The next session is September 1-3, 2026. Register now!

Intune Certificate Connectors

Don’t overlook Windows Server 2016 servers with the Intune Certificate Connector installed. Fortunately, this is one of the more manageable workloads to migrate. All that’s required is to install new connectors on supported servers and delete the old ones.

Summary

With extended support for Windows Server 2016 ending on January 12, 2027, organizations running production workloads—especially critical infrastructure such as Active Directory Certificate Services (AD CS), Certificate Authorities (CAs), and NDES servers—face significant security risks from unpatched vulnerabilities once the OS reaches end-of-life. Careful migration planning to newer versions such as Windows Server 2022 or 2025 is essential to minimize downtime, improve security posture, and ensure long-term resilience.

Start Planning Now

Don’t risk running unsupported workloads in 2027! Complete your migration today. If you’d like expert guidance, I have many years of experience migrating these workloads. I have developed specialized tools and techniques to ensure a smooth, secure, and successful transition. Fill out the form below to schedule a free one-hour consultation to assess your Windows Server 2016 AD CS workloads, identify migration risks, and outline next steps.

Additional Information

Windows Server 2016 Lifecycle Policy

PKI Fundamentals with Microsoft Active Directory Certificate Services (AD CS) Online Training Course

Mastering Enterprise PKI Certificates with Microsoft Intune Online Training Course

Microsoft Global Secure Access (GSA) Traffic Forwarding Profiles v2

Microsoft recently introduced custom Entra Private Access traffic forwarding profiles in public preview. Administrators can now provide different sets of private applications to selected users, groups, devices, and device platforms. This post explains how the profiles are assigned and prioritized, how to configure one, and how the new local network option handles overlapping address space.

Forwarding Profiles v1

Previously, organizations could assign the default Private Access traffic forwarding profile to selected users and groups, but they could not create separate Private Access profiles with different acquisition rules for different target groups. That made it difficult to give Windows devices one set of private application destinations and mobile devices another. Administrators could still control access through application assignments and Conditional Access, but the traffic the client acquired was less tailored to the user or device.

Forwarding Profiles v2

Global Secure Access (GSA) provides default traffic forwarding profiles for Microsoft traffic, Private Access, and Internet Access. Administrators can also create custom Private Access profiles and scope them to users, groups, devices, and device platforms. During the preview, a tenant can have up to 10 custom Private Access profiles.

Policy Processing

GSA evaluates traffic against the Microsoft, Private Access, and Internet Access profile types in that order. Traffic that matches none of them is not forwarded to the service. This order is separate from the priority used to choose between multiple applicable Private Access profiles.

Multiple Profiles

Each custom Private Access profile has its own acquisition rules, assignments, status, and priority. Assign a priority from 101 through 199. A lower number represents a higher priority. When more than one enabled Private Access profile applies to the same user and device, the client uses only the highest-priority applicable profile. The application rules from the other profiles are not combined with it.

Configure a Custom Private Access Profile

In the Microsoft Entra admin center, go to Global Secure Access > Connect > Traffic forwarding. Select Create new traffic forwarding profile, then Private access profile. Enter a descriptive name and, optionally, a description. Set a priority from 101 through 199 and choose whether the profile is enabled. Select Next, review the settings, and select Create. Note that the new profile has no acquisition rules or assignments until you configure them.

Acquisition Rules

Open the new profile and select Acquisition rules. Choose whether to include Quick Access destinations, then select the Private Access applications whose destinations the profile should acquire. Adding an application to a forwarding profile determines which traffic the client captures. Users must also be authorized to connect to the application’s resources.

Including Quick Access Destinations

Including Quick Access adds its configured destinations to the acquisition rules of this profile alongside the selected Private Access applications. This can provide a common set of destinations across custom profiles, but it does not change the Quick Access application’s configuration or grant users access to its resources. Confirm that the intended users are assigned to Quick Access as well as to the forwarding profile.

Assignments

Under Assignments, select View next to User and device assignments. Choose All users and devices or Selected users and devices, then save your selection.

Next, select View next to Device platform assignments and choose the supported platforms that should receive the profile. A device must match both assignment conditions. For example, selecting a user group and Windows limits the profile to Windows devices used by members of that group.

The new profile appears in the traffic forwarding list by priority, as shown here.

On an assigned client, open Advanced diagnostics > Forwarding profile to confirm that the expected Private Access application segments are present, as shown here.

Prefer Local Network

The Windows GSA client includes a Prefer local network option for cases where a local subnet overlaps with a configured private application destination. When an administrator enables the option, it appears in the client settings. A user can select it to keep applicable local subnet traffic on the local network, such as traffic to a printer or screen casting device, instead of having the client acquire that destination for Private Access. Microsoft introduced the option in Windows GSA client version 2.32.294.

The Problem It Solves

Overlapping private address space can make a local destination look like a destination defined in a Private Access application segment. For example, a user’s home printer and a corporate resource might both use 192.168.1.50. Prefer local network lets the user favor the directly connected local destination in this situation, such as when printing or screen casting.

Intelligent Local Access

Intelligent Local Access (ILA) serves a different purpose. It uses configured DNS probes to identify a corporate private network and can then send traffic directly to specified Private Access applications available on that network. Prefer local network addresses when there is an overlap between the device’s local subnet and a Private Access destination, such as a printer on a home network. ILA depends on a matching configured private network and application. An address overlap alone does not trigger it.

Summary

Custom Private Access traffic forwarding profiles give administrators more control over which private application destinations the Global Secure Access (GSA) client acquires for different users and devices. Assignments determine who receives a profile, while priority determines which profile applies when assignments overlap. The Prefer local network option also helps Windows users reach local devices when their subnet overlaps a Private Access destination.

Additional Information

Global Secure Access traffic forwarding profiles

Create a Private Access traffic forwarding profile

Entra Private Access Intelligent Local Access

Always On VPN Security Updates September 2026

Microsoft released the September 2026 security updates today, which include numerous fixes affecting Always On VPN deployments. This month’s edition addresses vulnerabilities in Windows Server Routing and Remote Access (RRAS), VPN protocols such as Secure Socket Tunneling Protocol (SSTP) and Internet Key Exchange version 2 (IKEv2). The updates also include Active Directory Certificate Services (AD CS), a crucial supporting infrastructure service for Always On VPN.

RRAS

September 2026 Microsoft security updates include 8 CVEs for RRAS. Four are rated Critical, the most severe having a CVSS rating of 9.8.

RCEs

The following four CVEs are Remote Code Execution vulnerabilities. All are rated critical.

Privilege Escalation

The following two CVEs are RRAS privilege escalation vulnerabilities. All are rated Important.

Denial of Service

Finally, the last CVE addresses a denial-of-service vulnerability in RRAS.

VPN Protocols

The following section outlines vulnerabilities addressed in the September 2026 security updates affecting commonly used VPN protocols.

SSTP

The following four CVEs cover vulnerabilities in SSTP. One is rated critical with a CVSS score of 9.8. The rest are rated Important.

IKEv2

The following CVEs address vulnerabilities in the IKEv2 VPN protocol. All are rated important.

AD CS

Microsoft AD CS is commonly deployed to issue and manage certificates used for encryption and user and device authentication in Always On VPN deployments. The following four CVEs address vulnerabilities disclosed in AD CS. The first two are privilege escalation vulnerabilities, the third covers information disclosure, and the last addresses a tampering vulnerability. All are rated Important.

Summary

The September 2026 Microsoft security updates address several critical vulnerabilities affecting organizations that have deployed Microsoft Always On VPN. Administrators are encouraged to update their systems as soon as possible.

Additional Information

Microsoft September 2026 Security Updates