When we use canonical hostnames (aliases/CNAMES etc..) in Mongo for hostname. Using Mongo.jar, the following call can be made to use Canonical host names: 

             MongoCredential credential = MongoCredential.createGSSAPICredential(user).withMechanismProperty("CANONICALIZE_HOST_NAME", true);

Mongo doc: http://api.mongodb.org/java/2.12/com/mongodb/MongoCredential.html#createGSSAPICredential(java.lang.String)

In ADS, we should add a new Driver parameter called caonicalHostName w/ values of true and false. Default is false.

We need to support this in v15 & v16.