In order to monitor two domaincontrollers in a customers LAN, I added the LDAP(s) sensor for each server. Both sensors were configured exactly the same way. At the moment they are in an error state but the errormessages are different.

One says: "The server is not working"

The other one says: "Username or password incorrect"

Im using LDAP over SSL on default port 636. I also tested it with another user but that is not working either.

Thanks for help!

Article Comments

Hi there,

Please make sure that a domain administrator is configured for the corresponding device in the settings. In addition, you can check if the SSL certificate is valid, by adding a SSL certificate sensor to the corresponding devices.

Kind regards,
Birk Guttmann, Tech Support Team


Jun, 2020 - Permalink

Thanks for the answer, I'll try that. Yes, the domain administrator is configured in the device settings.

Is the spelling of the distinguished name correct? cn=prtg,ou=users,dc=mydomain,dc=local


Jun, 2020 - Permalink

Hi Jannik,

Yes, the spelling of the distinguished name seems to be fine.

Kind regards,
Birk Guttmann, Tech Support Team


Jun, 2020 - Permalink

Same problem at my site. Only the non SSL works fine. Default-Settings used at port 636. Tried different DN's but same result.

Any news on this or a KB article how to solve this?


Feb, 2021 - Permalink

Meanwhile it's workling fine for me. To be honest, I just forgot one part of the Distinguished Name :D Found it out by activating the Advanced Features in my AD Users and Groups Editor, rightclicked the user I specified in the sensor settings in PRTG, opened properties and navigated to the attribute editor. There you can see the exact DN.


Feb, 2021 - Permalink