SNMPv3 was designed in the late 1990s, and in December of 2002 become a standard. It is defined in RFCs 3410 through 3415 [see Related protocol specifications]. SNMPv3 uses the basic SNMP management system and operations of SNMPv1 and SNMPv2, but adds an entirely new security architecture. The SNMPv3 architecture is modularized so that portions of it can be enhanced over time without requiring that the entire architecture to be replaced. SNMPv3 defines a framework that, among other things, includes the following models:
The framework is structured so that multiple models can be supported concurrently and replaced over time. For example, although there is a new message format for SNMPv3, messages that are created with the SNMPv1 and SNMPv2c formats are still supported. Similarly, the user-based security model can be supported concurrently with previously used community-based security models. In addition, SNMPv3 added other key updates to the protocol, such as the following updates:
A new notification type, INFORM, is like a TRAP that requires an acknowledgement. If the acknowledgment is not received, the INFORM is resent.
With SNMPv3, a TRAP can also be filtered at the sender.
The SNMP agent can be dynamically configured using MIB modules defined in RFC 3584 and RFCs 3411 through 3415.