NETWORK SUPPORT & TROUBLESHOOTING
These TechNotes will focus on a single exam objective:
4.9 Given a network problem scenario, select an appropriate course of action based on a general troubleshooting strategy. This strategy includes the following steps:
- Identify the symptoms and potential causes
- Identify the affected area
- Establish what has changed
- Select the most probable cause
- Implement an action plan and solution including potential effects
- Test the result
- Identify the results and effects of the solution
- Document the solution and process
Knowing the facts and details covered in the rest of our Network+ TechNotes will enable you to solve most of the scenario questions related to the exam objectives of Domain 4.0 Network Support. The rest comes down to knowing the steps listed above and described below.
You don't need to go thru all of the steps for every problem you will encounter and the order of the steps can differ slightly. Also, every step or subset of steps can be repeated multiple times. For example, you probably won't document a solution if it the solution was "disable caps lock". In many real world scenarios you also want to recognize the potential effects of the solution before you implement it. And if you implemented a solution and tested the results, the results might be negative and force you to go back and repeat previous steps.
If you carefully read a network problem scenario question in the Network+ exam, one or more of the first 3 steps will usually be provided (after all, we don’t have access to the system(s) that need troubleshooting so they need to provide you with some clear hints). For example: "A user calls you and says she can't logon to the network since her workstation has been moved to another office building." This includes pretty much all the information you need to complete step 1, 2, and 3. The following step would be to select the most probable cause and then to implement a solution.
The remaining part of the question could be: "Select the most probable cause: a. Incorrect TCP/IP settings b. Defective NIC c. Defective patch cable d. Incorrect password". In this case you'll have to select the most probable cause by combining your technical knowledge with plain logic. There is no reason to assume that answer b, c, or d is correct. Although they could all be the cause of the problem, they are less easy to relate to the move. More probable is that the other office building requires different TCP/IP settings.
Instead, the remaining part of the question could also be: "What would you do to solve the problem? a. Replace the workstation's NIC b. Reinstall the client's OS c. Reconfigure the client's IPX settings d. Replace the patch cable" This means they will assume you know the probable cause already and they skip right ahead to implementing a solution. The cause is mostly obvious and the best solution can be determined again by using your technical knowledge combined with plain logic. There is no reason to assume that answer a, or d is correct, and answer b is obviously incorrect. You should pick answer c because you assume the 2 buildings are connected with routers, meaning the IPX network number will be different in the other office.
Some scenario questions might include network diagrams on which you should apply the first 4 steps. Keep in mind that symptoms may be ‘indirect’ caused by the real cause of the problem. For example, a MAC OS X system not being able to access the Internet may very well be a problem with a Cisco router or Microsoft firewall. As with any exam: Read carefully!
Another possibility is that you'll be asked to choose the next step. For example, in the first scenario above, the remaining part of the question could be: "What is the next step you should take? a. Test the result b. Implement a solution c. Recognize the potential effects of the solution d. Select the most probable cause". The correct answer would of course be d. The chance that you might encounter a question like this, and the fact that it will make you more efficient in solving such problems, is reason enough to memorize these steps.