19.4. Schema Differences
Although Active Directory supports the same basic X.500 object classes as Directory Server, there are a few incompatibilities of which administrators should be aware.
Both Active Directory and Directory Server can enforce password policies such as password minimum length or maximum age. Windows Sync makes no attempt to ensure that the policies are consistent, enforced, or synchronized. If password policy is not consistent in both Directory Server and Active Directory, then password changes made on one system may fail when synched to the other system. The default password syntax setting on Directory Server mimics the default password complexity rules that Active Directory enforces.
Nested groups (where a group contains another group as a member) are supported and for WinSync will be synchronized. However, Active Directory imposes certain constraints as to the composition of nested groups. For example, a global group contain a domain local group as a member. Directory Server has no concept of local and global groups, and, therefore, it is possible to create entries on the Directory Server side that violate Active Directory's constraints when synchronized.
Active Directory uses the attribute streetAddress for a user or group's postal address; this is the way that Directory Server uses the street attribute. There are two important differences in the way that Active Directory and Directory Server use the streetAddress and street attributes, respectively:
In Directory Server, streetAddress is an alias for street. Active Directory also has the street attribute, but it is a separate attribute that can hold an independent value, not an alias for streetAddress.
Active Directory defines both streetAddress and street as single-valued attributes, while Directory Server defines street as a multi-valued attribute, as specified in RFC 4519.
Because of the different ways that Directory Server and Active Directory handle streetAddress and street attributes, there are two rules to follow when setting address attributes in Active Directory and Directory Server:
Windows Sync maps streetAddress in the Windows entry to street in Directory Server. To avoid conflicts, the street attribute should not be used in Active Directory.
Only one Directory Server street attribute value is synced to Active Directory. If the streetAddress attribute is changed in Active Directory and the new value does not already exist in Directory Server, then all street attribute values in Directory Server are replaced with the new, single Active Directory value.
For the initials attribute, Active Directory imposes a maximum length constraint of six characters, but Directory Server does not have a length limit. If an initials attribute longer than six characters is added to Directory Server, the value is trimmed when it is synchronized with the Active Directory entry.