Requesting certificates through the Network Device Enrollment Service (NDES) fails with HTTP error code 503 and there are no entries in the Event Viewer

Assume the following scenario:

  • A network device enrollment service (NDES) is implemented in the network.
  • The NDES server uses a domain account or a Group Managed Service Account (gMSA) for the identity of the SCEP IIS application pool.
  • Requesting certificates via NDES fails with HTTP error code 503 (Server Unavailable).
  • Calling the mscep and mscep_admin pages also fails with HTTP error code 500.
  • Even after an iisreset or restart of the NDES server, no event appears after calling the mscep or mscsp_admin page that the NDES service has started or that there were errors.
Continue reading „Die Beantragung von Zertifikaten über den Registrierungsdienst für Netzwerkgeräte (NDES) schlägt mit HTTP Fehlercode 503 fehl, und es gibt keine Einträge in der Ereignisanzeige“