The MIB (Management Information Base) is a hierarchical database defining the "variables" (objects) that can be monitored on a device. An SNMP trap is an "unsolicited message" sent by the agent to the manager to alert it of a specific event (like a link going down) without the manager asking for it. The SNMP agent is the software process running on the managed device that "responds to status requests" (Get/Set messages) from the manager. Finally, the SNMP manager (or management station) is the central entity that polls devices and collects data; it "resides on an NMS" (Network Management System).

Case, J., Fedor, M., Schoffstall, M., & Davin, J. (1990). A Simple Network Management Protocol (SNMP). IETF RFC 1157.

Section 3.2.1: Describes the "Management Information Base (MIB)" as a collection of managed objects.

Section 4.1.6: Defines the "Trap-PDU" regarding unsolicited event reporting.

Section 3.1: Discusses the architecture involving "network management stations" (Managers) and "network elements" (Agents).

DOI: https://doi.org/10.17487/RFC1157

Cisco Systems. IP Application Services Configuration Guide, Cisco IOS Release 12.4. "Configuring SNMP Support."

Section "SNMP Overview": Explicitly defines the SNMP manager as running on the NMS and the SNMP agent as residing on the managed device.

Section "SNMP Notifications": Defines traps as unsolicited messages.

Stallings, W. (1999). SNMP, SNMPv2, SNMPv3, and RMON 1 and 2. Addison-Wesley Professional.

Chapter 4: Covers the SNMPv1 architecture, defining the roles of the Manager, Agent, and MIB structure.