You must specify the port the DAS (Domain Administration Server) is running on. For example:
asadmin --host localhost --port 4848 enable-secure-admin
asadmin --host localhost --port 5858 enable-secure-admin
asadmin --host localhost --port 6868 enable-secure-admin
Of course, this assumes the ports are for d1, d2, and d3 respectively.
Hope this helps.