Simple Network Management Protocol

Management Systems and Agents

Utilizing SNMP services requires two components, as shown in Figure 10.2:

An SNMP management system.
An SNMP agent.

The SNMP management software application does not have to run on the same computer as the SNMP agents.

Figure 10.2 SNMP Management System and Agent

The SNMP management system, also known as the SNMP Management console, can request the following information from managed computers (SNMP agents):

Network protocol identification and statistics.
Dynamic identification of devices attached to the network (a process referred to as discovery).
Hardware and software configuration data.
Device performance and usage statistics.
Device error and event messages.
Program and application usage statistics.

The management system can also send a configuration request to the agent that requests the agent to change a local parameter; however, this is a rare occurrence because most client parameters have read-only access.

Several SNMP management tools are provided on the Windows 2000 Resource Kit companion CD. For more information about management tools, see "Architecture of Windows 2000 SNMP" in this chapter.

SNMP agents provide SNMP management systems with information about activities that occur at the Internet Protocol (IP) network layer and respond to management system requests for information. Any computer that is running SNMP agent software, such as the Windows 2000 SNMP Service, is an SNMP agent. The agent service can be configured to determine what statistics are to be tracked and what management systems are authorized to request information.

In general, agents do not originate messages — they only respond to messages. The exception is an alarm message triggered by a specific event. An alarm message is known as a trap message. A trap is an alarm- triggering event on an agent computer, such as a system reboot or illegal access. Traps and trap messages provide a rudimentary form of security by notifying the management system any time such an event occurs.

For more information about SNMP requests and trap messages, see "SNMP Messages" in this chapter.