Java Dynamic Management Kit 5.1 Tutorial

20.2.1 SnmpV3AdaptorServer

The SnmpV3AdaptorServer makes it possible to register an SnmpMibAgent that handles all varbinds whose OIDs are contained below a given node of the global OID tree. For each SNMP request, all varbinds that are relevant to the part of the OID tree handled by the SnmpMibAgent are grouped into an SnmpMibRequest and passed to the SnmpMibAgent. The concrete SnmpMibAgent implementation can be either a local MIB generated by the mibgen tool, or a remote MIB, configured with an SnmpProxy object.

The SnmpV3AdaptorServer enables you to register overlapping MIBs. The actual value returned to the manager is the value implemented by the deepest MIB registered for that value. This makes it possible to register, for example, a default SnmpMibAgent to which all unhandled OIDs are forwarded. An example of such a default subagent can be the Solaris subagent snmpdx, all the OIDs of which are neither handled locally nor handled by known subagents. This makes it possible to forward them to an SnmpProxy object that forwards to snmpdx and is registered at the root of the OID tree. This only requires registering such an SnmpProxy object at the root of the OID tree.

The SnmpV3AdaptorServer supports MIB scoping, namely, context names, and makes it possible to register a MIB within a given scope, that is, for a given context name. The SnmpV3AdaptorServer also makes it possible to extract context names from an SNMPv1 or SNMPv2 community string. The master agent function can thus be spawned over several context names. A specific context name can be dedicated to a specific subagent, enabling you to register a single SnmpProxy object at the root of the OID tree for a given context name. The context name can also be shared between several subagents, and possibly local MIBs, as described above.