User Manual

User’s Guide Chapter 5 – SNMP Management
authenticationFailure
An authenticationFailure trap signifies that the SNMP entity, acting in an agent role, has
received a protocol message that is not properly authenticated.
linkDown
A linkDown trap signifies that the SNMP entity, acting in an agent role, recognizes a failure in
one of the communication links represented in the agent's configuration.
linkUp
A linkUp trap signifies that the SNMP entity, acting in an agent role, recognizes that one of
the communication links represented in the agent's configuration has come up.
SNMP Agent
The SNMP agent is integrated in your P-520r and responds to SNMP manager requests as follows:
 Get a MIB variable—The SNMP agent begins this function in response to a request from the
SNMP manager. The agent retrieves the value of the requested MIB variable and responds to the
manager with that value.
 Set a MIB variable—The SNMP agent begins this function in response to a message from the
SNMP manager. The SNMP agent changes the value of the MIB variable to the value requested
by the manager.
The SNMP agent also sends unsolicited trap messages to notify an SNMP manager that a significant
event has occurred (e.g. authentication failures) on the agent.
SNMP Community Strings
SNMP community strings authenticate access to MIB objects and function as embedded passwords.
In order for the SNMP manager to access the controller, the community string must match one of the
two community string definitions on the controller. A community string can be as follows:
 Read-only – gives read access to authorized management stations to all objects in the MIB
except the community strings, but does not allow write access.
 Read-write – gives read and write access to authorized management stations to all objects in the
MIB, but does not allow access to the community strings.
The SNMP Read-write community string is also the administrator’s password. If the
password is changed the SNMP community string will be changed as well.
Use SNMP to Access MIB
As shown in the picture Figure 74 – SNMP Network SNMP agent gathers data from the MIB. The
agent can send traps (notification of certain events) to the SNMP manager, which receives and
processes the traps. Traps are messages alerting the SNMP manager to a condition on the network
such as improper user authentication, restarts, link status (up or down), MAC address tracking, and so
forth. The SNMP agent also responds to MIB-related queries sent by the SNMP manager in get-
request, get-next-request, and set-request format.
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