1. In a computing environment, a method of determining which object classes are supported by a given network device, comprising: a) traversing trees of groups to create a range table of groups and corresponding ranges of object identifiers; b) selecting a range starting object identifier from the range table; c) requesting that the network device to return its next highest object identifier beyond the selected object identifier; d) receiving a returned object identifier; e) determining whether the returned object identifier falls into a range in the table, and if so, maintaining information that a group corresponding to that range is supported; and f) returning to b) using remaining ranges to provide starting object identifiers until the range table has no untested entries remaining.