SNMP Version 3 shares the same basic architecture of Version 1, but adds numerous enhancements to SNMP administration and security. The primary enhancement relevant to Enterprise Manager involves additional security levels that provide both authentication and privacy as well as authorization and access control.

User-based Security Model (USM)

USM defines the security-related procedures followed by an SNMP engine when processing SNMP messages. Enterprise Manager SNMP V3 support takes advantage of this added SNMP message-level security enhancement to provide a secure messaging environment.

USM protects against two primary security threats:

• Modification of information: The modification threat is the danger that some unauthorized entity may alter in-transit SNMP messages generated on behalf of an authorized principal in such a way as to effect unauthorized management operations, including falsifying the value of an object.

• Masquerade: The masquerade threat is the danger that management operations not authorized for some user may be attempted by assuming the identity of another user that has the appropriate authorizations.

For both SNMP versions, the basic methodology for setting up Enterprise Manager advanced notifications using SNMP traps remains the same:

1. Define the notification method based on an SNMP trap.

2. Assign the notification method to an incident rule.