Where the record is.
WHAT LOGS EXIST
Router logs Device logs Web server access and error logs Mail logs Application logs
WHAT ACCESS LOGS SHOW
Every request: when, from where, for what, and the result.
WHAT ERROR LOGS SHOW
What failed, and frequently exactly why.
WHY THEY MATTER
They replace guessing with fact.
WHAT TO LOOK FOR
The time the problem occurred Entries immediately before it Repetition
WHAT REPETITION INDICATES
Automated activity, or a loop.
WHAT TO CHECK FOR A SITE PROBLEM
The error log first.
It usually names the file and the line.
WHAT TO CHECK FOR A MAIL PROBLEM
Whether the message was accepted, deferred or rejected, and the reason given.
WHAT TO BE CAREFUL WITH
Log times, which may be in a different time zone.
Establish which before correlating.
WHAT TO KEEP
Relevant extracts, when reporting a problem.
