What is SNMP?

SNMP is a part of the TCP/IP protocol suite. It was originally developed in the Internet community to monitor and troubleshoot routers and bridges. SNMP transports management information and commands between a management system and an SNMP agent, with management tools such as Hewlett-Packard® OpenView, IBM® NetView®, and Sun® Net Manager. The SNMP agent sends status information to one or more hosts when the host requests it or when a significant event occurs.

These are some of the entities that administrators can use SNMP to monitor and control:

• • Computers running Windows NT
• • LAN Manager servers
• • Routers or gateways
• • Bridges and concentrators
• • Minicomputers or mainframe computers
• • Terminal servers

The primary function of a management system is to request information from an agent. A management system can initiate the get, get-next, and set operations.

• • The get operation is a request for a specific value, such as the amount of hard disk space available.
• • The get-next operation is a request for the "next" value. This operation traverses a conceptual table of objects.
• • The set operation changes the value of a variable. Only variables with read-write access can be set.

The primary function of an agent is to perform the get, get-next, and set operations requested by a management system. The only operation initiated by an agent is a trap, which alerts management systems to an extraordinary event, such as a password violation.