A company suffers an outage due to a bad module in a core switch. Which of the following is the proper order of troubleshooting?
A. Gather information, start at the top of the OSI model, and work down.
B. Establish a plan of action to solve the problem.
C. Establish a theory, identify the problem, duplicate the problem, test the theory, and repeat.
D. Gather information, start at the bottom of the OSI model, and work up.