Appstack requires Write access to integrate AD authentication. Appstack has the capability to manage (create, update and delete) users in Active Directory.
It is recommended to have dedicated OU for Appstack Integration. Users and Computers objects that are created in Appstack will be placed in the OU container. That way, any operational activity from Appstack will have no or minimal impact to existing Active Directory environment.
The Write access is only one way direction which is from Appstack to Active Directory, therefore any users created in Active Directory will not be automatically created in Appstack. To allow these users to access Appstack Portal, "Create User on The Fly" option has to be enabled in Admin Site Preference. It can be found in Authentication under General. The feature will enable Appstack to query new users in AD during logon authentication. If found, users will be created in Appstack database.