help on subschema

[paul k]

Hi all,
how do I query the servers subschema entry  for supported objectclasses? 
Searching like:

conn.search_s('cn=subschema',ldap.SCOPE_SUBTREE, '(objectclass=*)')

returns ldap.NO_SUCH_OBJECT. I cannot firute out how to get operational 
attributes.I looked at ldap.schema.subentry.SubSchema but could not 
figure out how to use it.

thanks
  Paul