InterMapper treats an outage on each device interface as a separate alert event. Each time an interface goes down, the device will go into alarm. The device icon turns orange, and the affected interface gets a red "X". Any Alarm notifications for that device are triggered.
You can right-click an affected interface's link, and select "Acknowledge". The device turns back to green (or its previous state/color), the interface link gets a blue "X", and no further notifications for that device are sent. InterMapper also writes a line in the Event Log file for these events. The format of the Event Log entries is:
09/30 14:03:32 link DOWN : [1] switch.example.com - 1 ... 09/30 14:03:49 link ACK : [1] switch.example.com - 1
If another interface subsequently goes down, the same process repeats:
If two interfaces go down more or less simultaneously, a single set of alarm notifications is sent. If you right-click to acknowledge one interface, the device itself remains orange because it still has unacknowledged down interfaces. No further notifications will be sent. When all the down interfaces have been acknowledged the device returns to its previous state and color.
Once acknowledged, a link's Status Window show the interface's status as "ACK (down)".
You can acknowledge and unacknowledge multiple interfaces from the device's Interfaces Window. Select one or more interfaces in the list, and choose Acknowledge or Unacknowledge. This has the same effect as doing each interface individually.
You can un-acknowledge a link by right-clicking on it. This replaces the blue "X" with a red one, and re-enables any repeated notifications for that device.
Tip: Choose from two methods of handling down interfaces.