The SNMP poller’s MIB variable poll list is driven by a Just-In-Time polling algorithm, which ensures that only those MIB variables needed for correlation are polled. For example, if a port monitored for performance data is disabled, or goes down, the SNMP poller automatically removes the relevant MIB variables from the poll list. If the port is reenabled, or comes back up, the variables are automatically put back onto the MIB poll list.