Problems that come and go.
WHY THEY ARE HARD
They are absent when you look.
WHAT TO DO
Record every occurrence: time, what failed, what was happening.
WHY
Patterns emerge from records and never from memory.
WHAT PATTERNS TO LOOK FOR
Time of day Coinciding with a scheduled task Coinciding with heavy use Weather, for wireless links After a particular device connects
WHAT COMMONLY CAUSES INTERMITTENT NETWORK FAULTS
A failing cable or connector Overheating equipment An address conflict Wireless interference A device saturating the connection Equipment nearing failure
THE OVERHEATING POINT
Faults that appear after hours of operation and clear after a restart suggest heat.
THE CONFLICT POINT
Two devices misbehaving at once suggests an address conflict.
WHAT TO DO
Change one variable and observe over time.
WHAT TO ESCALATE WITH
The log of occurrences.
Without it, intermittent faults are dismissed.
