8.12 Troubleshooting the Network
8.12.1 Troubleshooting approach
An example of a troubleshooting approach involves the following four steps:
  1. Determine if the problem exists across the network. Is the problem across the network or in a portion of the network? Identifying the scale of the problem will determine how many users are affected and may provide clues as to what caused(or is causing) the problem.
  2. Attempt to isolate the problem. Is one workstation not functioning; is that client able to connect to the network? Or is it the entire workgroup not functioning; are any of the devices able to print? Or is the problem effecting the entire LAN; is it the entire Ethernet segment that is not functioning? Or is it a WAN problem, or a problem with the LAN-WAN connection, for example, do the clients have Internet access?
  3. Determine if the problem is consistent. Is the problem continuous and not intermittent? In other words, is the problem constantly present, instead of occurring periodically or randomly? And can the problem be replicated: given the same conditions on the same machine or another, the same errors are present? This information will help determine what may be causing the problems on the network.
  4. Finally, determine if the problems can be resolved by using tools. A set of standard tools for maintaining networks should be available. These tools include hardware tools (such as cable testers), software tools (such as protocol analyzers), workstation and server commands, software, and utilities,web-based and text-based hardware and software manuals, and diagnostics that come with various network components, such as servers, NICs, hubs, switches, and routers.