Which function does an SNMP agent perform?
An SNMP (Simple Network Management Protocol) agent is software running on a network device that collects and organizes management information about the device and makes this information available to network management systems (NMS) using SNMP. The SNMP agent communicates with the NMS using SNMP messages, which are typically carried over UDP/IP.
The correct answer to this question is A: "It sends information about MIB variables in response to requests from the NMS." The SNMP agent performs this function by responding to SNMP requests from the NMS for specific pieces of management information. This information is organized into a hierarchical structure called the Management Information Base (MIB).
The MIB contains information about various aspects of the network device, such as its configuration, performance, and status. The SNMP agent gathers this information from the device and stores it in the MIB. When the NMS sends an SNMP request for a particular piece of information, the SNMP agent retrieves the information from the MIB and sends it back to the NMS in an SNMP response message.
Option B, "It manages routing between Layer 3 devices in a network," describes the function of a routing protocol, not an SNMP agent. Routing protocols are used to exchange routing information between routers and to determine the best path for forwarding data packets.
Option C, "It coordinates user authentication between a network device and a TACACS+ or RADIUS server," describes the function of an authentication protocol, not an SNMP agent. Authentication protocols are used to authenticate users and control access to network resources.
Option D, "It requests information from remote network nodes about catastrophic system events," describes the function of a monitoring protocol, not an SNMP agent. Monitoring protocols are used to detect and report on system events, such as failures or anomalies, in real-time.