We currently run Windows Server 2016 as our domain controller platform and are planning an upgrade. Most of our other servers, including on-premises Exchange, have already been migrated to Windows Server 2025. The question is whether to move directly to Server 2025 for the longer support lifecycle or use Server 2022, which has had more time to mature.
I remember reports of serious early problems involving Server 2025 domain controllers, particularly in mixed-version environments. For organizations running it in production, how reliable is it now? Have you encountered problems with Active Directory, DNS, replication, Group Policy, Kerberos, machine trust relationships, or older applications? We intend to replace the 2016 domain controllers rather than maintain a long-term mixed environment, so practical migration experience would be especially useful.
5 Answers
The safest recommendation from the discussion is Server 2022. It is mature, stable, and still receives security updates for years, while most domain-controller deployments do not need the newer features in Server 2025. Several administrators reported that promoting a 2025 controller into an existing 2016, 2019, or 2022 environment caused authentication failures, broken SYSVOL, computer trust errors, or machine-password rotation problems. Removing it and replacing it with Server 2022 resolved the issues for them.
Server 2025 is not universally broken. A number of organizations have run it successfully for a year or more, including environments that migrated from older versions. The smoother deployments tended to be simple or fully modernized environments, with all domain controllers eventually running 2025 and legacy dependencies already removed. Early releases had more severe bugs, so current patch levels and careful testing matter a lot.
Mixed-version domains are where most of the serious reports seem to come from. Administrators have seen intermittent Kerberos failures, computers losing their domain trust, users being unable to log in, machine-account password mismatches, and problems with SMB or SYSVOL. Some sites report no issues at all, but the failures can be difficult to reproduce and may only appear after weeks. I would avoid making 2025 the only authentication platform until it has been tested alongside your actual clients and applications.
Before choosing 2025, audit the environment rather than treating this as a normal operating-system upgrade. Check legacy Kerberos encryption such as RC4, unsigned LDAP binds, LDAP channel binding, service-account dependencies, constrained delegation, GPO settings, endpoint security software, cloned machines, and backup/restore procedures. Newer security defaults can expose old systems that happened to work with the previous domain controllers. Do not solve that by broadly re-enabling insecure protocols; identify and replace the dependent systems instead.
A practical migration path would be to introduce a Server 2022 domain controller first, transfer the roles, verify DNS, replication, SYSVOL, authentication, GPO processing, and application integrations, then retire the 2016 controllers. Run the 2022 setup for a while and only test 2025 in a separate lab or as a carefully monitored additional controller. If you ultimately move to 2025, keep reliable system-state backups, document a rollback plan, and stage the rollout rather than replacing every controller at once.
It is also possible to deploy newer domain controllers while keeping the domain and forest functional levels lower. That provides the newer operating-system support window without immediately enabling every new AD feature, but it does not eliminate compatibility problems between 2025 and older controllers.