The interface is up and operational. The interface is able to pass packets.
isDown
The interface is not down and not operational. The interface is unable to pass packets.
isTesting
The interface is being tested.
isUnknown
The interface status is unknown.
isDormant
The interface is not in a condition to pass packets. The interface is not up, but is in a pending state, waiting for some external event. This state identifies the situation where the interface is waiting for events to place it in the up state.
isNotPresent
This state is a refinement on the down state which indicates that the interface is down specifically because some component (for example, a hardware component) is not present in the system.
isLowerLayerDown
This state is a refinement on the down state. The interface is operational, but a networking layer below the interface is not operational.