Problem-Solving Checklist/Worksheet

To isolate problems in your internetwork, you must first compile all the relevant facts and then methodically address each suspect problem. This appendix provides a troubleshooting checklist and general worksheet to help you in this process. Use the checklist and worksheet provided here as initial guidelines to assist you in developing your own checklist and worksheet--one tailored to your own internetworking environment.

Troubleshooting Checklist

Before you start making any changes to your internet, be sure you can answer the following questions positively:

Have you identified and compiled a list of all the reported symptoms on your internet?

Do you know your internetwork? Do you have an accurate physical and logical map of your internet?

Do you have a list of all the network protocols implemented in your network?

Do you know which protocols are being routed?

Do you know which protocols are being bridged?

Do you know all the points of contact to external networks?

For every symptom, have you developed a list of potential problems and causes?

For each problem, do you have a plan of action?

If you can answer yes to these questions, you can begin the process of problem isolation. Remember: eliminate one problem at a time.

Troubleshooting Worksheet

Symptoms reported:

2. .	Network Topology Map--attach separate sheet(s)

.	Protocols routed:

.	Protocols bridged:

.	Media used in your environment:

.	Internet equipment (including network address, vendor, model, and function):

.	Suspect end system and internet nodes (including network address, vendor, model, and function):

.	Applications being used on the network (FTP, sendmail, NFS, NetWare, etc.):

.	Symptoms and likely problems:

Symptom		Possible Problems

.	Action plan for each problem:

Problem		Action Plan

.	Action outcomes:

Problem/Action		Result/Outcome