Redundant SNMP agent

The SNMP driver can establish connection to a redundant SNMP agent in case the first agent is not available anymore. The driver communicates only with one agent at the same time. To configure a redundant SNMP agent refer to Configuration of the SNMP driver. The second agent (if correctly configured) is only alive checked. The driver only switches to the second agent if the first agent is not available anymore.

There is no preferred agent, which means that the driver does not switch back to the first agent. The driver communicates with second agent as long as it is available. If it is not available anymore, the driver switches back to the first agent.

In case of an agent switch, the driver sends the last unsuccessful request to the second agent. If the second agent is also unavailable the request is discarded.

After startup, the driver will always try to communicate with the first target.

Redundancy switch

Depending on the SNMP agent configuration the driver can switch to the redundant agent in the following cases:

• redu switch on timeout: defines if an agent switch shall be performed if the response of a read or write request returns the TIMEOUT status

• redu switch on keepAlive-error: defines if an agent switch should be performed if a keepAlive check fails

• redu switch on timeout and/or keepAlive-error: defines if an agent switch shall be performed if a keepAlive check fails or a read/write request returns the TIMEOUT status