Ideally I would probably design my "Node down" type alert with an or in the trigger condition, so something like
interface status is down OR event such and such happens
so that the down alert triggers on whichever thing it sees first, status change or a trap, and it won't re-trigger because its already active.
I haven't done any interface alerting yet with LM, for all the events i was working with it was automatically attaching all the trap events to the Node and didn't see anything that made me think we could associate events to the specific interfaces. If it is node level then it's going to be a real pain, probably end up requiring custom sql/swql to make an alert logic that covered both scenarios. Hopefully a PM can weigh in on interface alerting from LM events.
Gave it a try. The Orion Log Manager created alert had it set to "I want to alert on Nodes"
The out the box interface alert in alert manager is set to "I want to alert on Interfaces" (Which I suspect is correct).
I created a new "Or" Alert, copied the log manager alert condition and added an "OR" statement. Got a validation error..