We recommend using nltest tool from a domain-joined workstation (not necessarily the server that will run EasySSO-enabled Atlassian application) to discover all AD sites.
Please note, this assumes that the domain of the workstation that you are using is the same as the domain of the computer account you've specified in the EasySSO configuration screen.
nltest /dclist:
If you want to query just the domain of the computer account you've specified in the EasySSO configuration screen use the following syntax:
nltest /dclist:mydomain.com
AD Site name is a label for a group of 1 or more domain controllers, not an individual controller name.
Here is an example output - the AD Site name is on the right and is "mainoffice":
If multiple sites are returned you will need to establish which one should be used from the server that will run the application, as others may not be accessible and will cause intermittent errors with EasySSO not being able to reach the domain controllers while rotating through the list in a round-robin fashion (ironically for the sake of fault tolerance). The chosen site name should be entered in AD Site parameter in the EasySSO config screen.
If you have a list of known working Domain Controllers - choose the site that these belong to.
You can identify which controllers are working by running a grep command over jespa.log captured with log level 4.
$ grep -B2 -e "maps to port" jespa.log | grep DNS 2017-04-28 09:12:32: DNS: 'A' record lookup for dc1.domain.com at the default server 2017-05-03 11:29:49: DNS: 'A' record lookup for dc1.domain.com at the default server 2017-06-11 07:59:00: DNS: 'A' record lookup for dc2.domain.com at the default server
The following command will tell you what AD site the workstation you are running the command on is using. If your server is a Windows machine, joined to the domain - run the command there, otherwise note that if the workstation is not the server where you are running the Atlassian application, the returned result may be different from the site that should be used on the server.
nltest /dsgetsite