active directory
846 Topics2026-04 Update Breaks Domain Logins
I have an Active Directory domain that is old (from 2000!) that has been upgraded and moved to newer versions of Windows Server and Active Directory. I have domain controller VMs running Windows Server 2025 Standard Edition. Unfortunately they installed the latest 2026-04 patches which my have changed the Kerberos encryption from RC4 to AES. This has resulted in my not being able to log into any Active Directory domain accounts and the domain controllers themselves. I can only log into workstations using the local account. Suffice to say this a nightmare. Any ideas how to fix it since I can't access the usual tools like Active Directory Users and Computers, Hyper-V won't connect to the VMs, etc. Thanks. SSolved437Views2likes2CommentsProcedures to raise the functional level of AD 2008 r2 to 2019
Hello everyone, Our AD has the Windows Server 2008 functional level and the servers with Windows Server 2016 OS. I intend to raise the functional level to 2019 or 2025. I would like your help with tips and documentation to decide whether 2019 or 2025 would be best, what are the risks and procedures for successful migration. I have an isolated environment to carry out rehearsals and tests before actually going into production.28Views0likes1CommentDomain users not able to logon with their password event though it has not been changed....
Hi, we have this weird problem where some of the users suddenly can't login to their computer with the password they have used for almost 20 years (yes sorry, bad practise). When the user reports it I check that I can logon to the computer with my own account (not 20 year old password) which works fine. I check the event log for problems both on the client and the DC and all I see is see which I can relate to the problem is event id 4625 with an error code which means bad password. I check the AD account and see that pwdLastSet has a date in 2006 (not quite 20 years, but close) and I check that the account is not logged out or expired. Also make sure that the password never expires is enabled, so in my book these are all the checks needed and problem not solved. I then change the password to the same password that the user has had for almost 20 years and problem solved, but problem source not found. This has happend to 3-4 users within the last week or two, even a service user with domain admin permissions, only thing I pay note to that they have in common is the pwdLastSet in 2006, but I really can't seem to get my head around this being the issue. Also only other thing I can think of that has changed is that the old DC has been removed a few months ago, and a new 2025 DC has been introduced. promote/demote went without issues and this problem didn't surface before now several weeks after the DC change. So if anyone has experienced something similar or perhaps can point me in a direction for further troubleshooting please let me know. Thansk Thomas64Views0likes1CommentError al agregar Windows Server 2025 a dominio existente, nivel funcional 2016
Buenas a todos, Me dirijo a esta comunidad en busca de orientación para resolver un problema que se me está presentando al intentar integrar un nuevo servidor con Windows Server 2025 Standard a mi infraestructura de Active Directory existente. Descripción del entorno: Dominio de Active Directory activo con Windows Server 2019 Standard. Nivel funcional de dominio y bosque configurado en Windows Server 2016. Controladores de dominio actuales: server-dc01.impresoratec y server-ad2019.impresoratec. El nombre de dominio interno utilizado es impresoratec (nombre NetBIOS/dominio de etiqueta única, sin sufijo DNS completo tipo .local o .com). Problema: Al intentar agregar el nuevo servidor con Windows Server 2025 al dominio, el proceso falla y se presenta el siguiente mensaje de error: "Es posible que el nombre de dominio "impresoratec" sea un nombre de dominio NetBIOS. Si este es el caso, compruebe que el nombre de dominio está registrado correctamente con WINS. [...] La consulta se refería al registro SRV para _ldap._tcp.dc._msdcs.impresoratec. La consulta identificó los siguientes controladores de dominio: server-dc01.impresoratec y server-ad2019.impresoratec. Sin embargo, no se pudo contactar con ningún controlador de dominio." El mensaje sugiere que los registros de host (A) o (AAAA) pueden contener direcciones IP incorrectas o que los controladores de dominio no son accesibles desde el nuevo servidor. Lo que he verificado hasta ahora: Los controladores de dominio existentes están en línea y operativos. La replicación entre los DCs actuales funciona con normalidad. El nuevo servidor con 2025 tiene conectividad de red general, pero no logra localizar los DCs al momento de unirse al dominio. Mi consulta: ¿Alguien ha experimentado este comportamiento al incorporar un servidor con Windows Server 2025 a un dominio con nivel funcional 2016 y un nombre de dominio de etiqueta única (single-label domain)? ¿Existe algún requisito previo adicional —como la actualización del esquema de AD, ajustes en DNS o en WINS— que deba cumplirse antes de agregar el nuevo DC? Agradezco de antemano cualquier orientación o experiencia que puedan compartir.14Views0likes0Commentsdcdiag crash with incorrect /s parameter
Hello, I find a mistake in my script which cause DCDiag to crash : dcdiag /v /c /d /e /s:%computername% > C:\Temp\dcdiag.txt %computername% is the mistake. I replaced it by the real server name. Seems like input it not enough checked. VincentSolved44Views0likes1CommentBeyond RC4 for Windows authentication - Question regarding KB5073381
In KB5021131 MS recommends setting the value for DefaultDomainSupportedEncTypes to 0x38, in the new KB 5073381 it's 0x18. This removes the setting that forces "AES Session Keys" which should be fine if Kerberos Tickets can only use AES Encryption. But what about accounts that have RC4 enabled in their msds-supportedEncryptionTypes attribute? They could still use RC4 for Kerberos ticket encryption and would then also fallback to RC4 session ticket encryption. As far as I believe the DefaultDomainSupportedEncTypes was explicitly introduced to avoid this scenario. Or is there now some hard-coded mechanism that always ensures that Session Keys are AES encrypted?1.1KViews1like2CommentsLots of DNS Server events 5504 on AD DNS server from Cloudflare etc
Hi! I'm getting about 18 events with id 5504 while trying to resolve some DNS names, like fullfiles.xyz. The DNS server is configured to use provider DNS and root hints. I can suppress these messages by disabling root hints or by disabling EDNS0 with dnscmd /config /enablednsprobes 0. I tried to use packet capture on the DC and on the router, and analyzed the results with AI, which answered: "You receive malformed patterns on the WAN interface." Can anybody explain the cause of this problem? Any ideas to fix it? Thanks!192Views0likes1CommentIssues with Group Policy Update (gpupdate)
I am getting an error when I attempt to perform a gpupdate /force on workstations. I have checked the health of the DC's and find no issues. I am going to include a screenshot of the error - hoping someone can guide me as on how to resolve. The system will say to reboot but the policy never seems to run just keeps prompting for reboot.264Views0likes1CommentTurning Off Tamper Protection on Workstations
How do I turn off Tamper Protection on a domain-joined Windows 11 workstation? The problem is a workstation has Windows Defender in Passive Mode instead of being in Not Running mode after installing a 3rd party antivirus. Windows Defender is making running network applications from the servers much slower because it's still real-time scanning. I also suspect Tamper Protection is also preventing network drive exclusions from working on this workstation and on the ones that use Windows Defender without a 3rd party antivirus. I've tried adding every registry entry, Group Policy, and PowerShell command on the local workstation I could find to disable Windows Defender, but nothing works. I'm assuming this is due to Tamper Protection ignoring everything? This is an on-premises domain and doesn't use Microsoft Intune or Microsoft Endpoint Configuration Manager.Solved505Views0likes2Comments