4 Fast Ethernet Switch Management Guide

Simple Network Management Protocol

3-37

Simple Network Management Protocol

Simple Network Management Protocol (SNMP) is a communication protocol

designed specifically for managing devices on a network. Equipment commonly

managed with SNMP includes switches, routers and host computers. SNMP is

typically used to configure these devices for proper operation in a network

environment, as well as to monitor them to evaluate performance or detect potential

problems.

Managed devices supporting SNMP contain software, which runs locally on the

device and is referred to as an agent. A defined set of variables, known as managed

objects, is maintained by the SNMP agent and used to manage the device. These

objects are defined in a Management Information Base (MIB) that provides a

standard presentation of the information controlled by the agent. SNMP defines both

the format of the MIB specifications and the protocol used to access this information

over the network.

The switch includes an onboard agent that supports SNMP versions 1, 2c, and 3.

This agent continuously monitors the status of the switch hardware, as well as the

traffic passing through its ports. A network management station can access this

information using software such as HP OpenView. Access to the onboard agent

from clients using SNMP v1 and v2c is controlled by community strings. To

communicate with the switch, the management station must first submit a valid

community string for authentication.

Access to the switch using from clients using SNMPv3 provides additional security

features that cover message integrity, authentication, and encryption; as well as

controlling user access to specific areas of the MIB tree.

The SNMPv3 security structure consists of security models, with each model having

it’s own security levels. There are three security models defined, SNMPv1,

SNMPv2c, and SNMPv3. Users are assigned to “groups” that are defined by a

security model and specified security levels. Each group also has a defined security

access to set of MIB objects for reading and writing, which are known as “views.”

The switch has a default view (all MIB objects) and default groups defined for