Read this technical paper, which explores the effort in various scenarios to "target" troubleshooting as much as possible. This minimizes the extraneous output, which usually has no relevance to the problem at hand. An added bonus is minimizing the impact on the CPU of the appliance that would be understandably burdened by a more generalized "debug any" approach and could negatively impact throughput. This report highlights the effective use of the debug packet tool on an older operating system, and newer capture and packet tracer tools, the last of which can be used without involving the end-user.