The logic behind these alarms:
Most application and port models will not poll on their own, but instead use the parent device's contact status to determine their own contact status and condition. These are then set to mirror the parent (models polling on their own will determine their own status and condition). However, each such app/port does have its own set of communication attributes, which are used in any communication with the device that any logic attached to that app/port attempts. Normally these will simply be rolled down from the device, however they can be set to any value of their own as well.
Now, if such a communication attempt from the app/port fails (times out), but the device is still up, it could be for two reasons:
- The device is down (or temporarily unreachable). If the communication attributes on the app/port and the device match, Spectrum can send out an echo request from the device model to reconcile the contact status difference. Whatever the response (good/time out) for that echo request is will then determine the contact status of both the device and app/port. It will then either be good (green) for both, or the device will be lost (critical) and the app/ports suppressed.
- In case the communication attributes do not match, however, the app/port timeout could be because some of these differences (example: a different community string, with no more access to the device, or an incorrect network address). Spectrum cannot simply ask the device if it is up, since it is using different values, and Spectrum also cannot simply suppress the app/port, as the device is up (or, even if lost, there are no guarantees that the app/port's values will allow communication when the device is reachable again). So if Spectrum ever gets a timeout for an app/port where the communication attributes don't mirror the ones on the device, the Spectrum alerts the user of this condition, that there was a problem with the communication which may stem from the differences. The user can then either check if these attributes make sense or sync up these parameters again so that Spectrum can continue to mirror the device's contact status on the app/port model.