3Com 4007, Руководство по внедрению, Страница: 625 / 684

SNMP 625
SNMP Overview The following sections provide an overview of SNMP.
Manager/Agent Operation
SNMP communication requires a
manager
(the station that is managing
network devices) and an agent (the software in the devices that talks to
management station). SNMP provides the language and the rules that the
manager and agent use to communicate.
Managers can discover agents:
■
Through autodiscovery tools on Network Management Platforms
(such as HP OpenView Network Node Manager)
■
When you manually enter IP addresses of the devices that you want to
manage
For agents to discover their managers, you must provide the agent with
the IP address of the management station or stations.
Managers send requests to agents (either to send information or to set a
parameter), and agents provide the requested data or set the parameter.
Agents can also send information to the managers (without being
requested by the managers) through trap messages, which inform the
manager that certain events have occurred.
SNMP Messages
SNMP supports queries (called messages ) that allow the protocol to
transmit information between the managers and the agents. Types of
SNMP messages:
■
Get and Get-next — The management station requests an agent to
report information.
■
Set — The management station requests an agent to change one of
its parameters.
■
Get Responses — The agent responds to a Get, Get-next, or Set
operation.
■
Trap — The agent sends an unsolicited message informing the
management station that an event has occurred.