3Com 10014299 manual Snmp Overview, Development of Snmp

5	CONFIGURING NETWORK
	MANAGEMENT

This chapter includes information on the following topics:

■SNMP Overview

■RMON Overview

SNMP Overview	Simple Network Management Protocol (SNMP), a widely accepted industry
	standard, is the most dominant network management protocol in computer
	networks by far. It is developed to ensure transmission of management
	information between any two nodes, which will facilitate network administrators
	to search for information at any node on the networks for the purpose of
	modifying, locating faults, troubleshooting, planning capacity and generating
	reports. Adopting the polling mechanism, SNMP provides essential functionality,
	and is suitable for a networking environment requiring small size, high speed and
	low cost. Since it uses the transport layer protocol UDP (User Datagram Protocol)
	which requires no acknowledgement, it gains wide support in many products.

SNMP system comprises an NMS (Network Management Station) and an agent. NMS is the workstation running the client application. It sends various request packets to the managed network devices, receives the response and trap packets from the managed devices, and displays status information of the managed devices. The agent is a process running on the managed equipment. It receives and processes the request packets from the NMS, and responds to the NMS by returning the corresponding management variables obtained from the protocol module of the managed equipment. Whenever the agent detects the occurrence of emergency events on the managed device, such as a change in the interface status or a failed call, it will send traps to notify the NMS. The relationship between NMS and agent is shown in the following figure:

Figure 34 Relationship between NMS and agent

Trap

Response

Router	Request	NMS
	Ethernet

SNMP is the most widely applied communication protocol between NMS and

Agent in the computer network.

Development of SNMP

There are three versions of SNMP: SNMPv1, SNMPv2c and SNMPv3. SNMPv3 defines a series of access control management functions for network security, in