To quickly resolve network problems, take the time to select the most effective network troubleshooting method. The figure illustrates this process.
The following is an example of how to choose a troubleshooting method based on a specific problem:
Two IP routers are not exchanging routing information. The last time this type of problem occurred it was a protocol issue. Therefore, choose the divide-and-conquer troubleshooting method. Analysis reveals that there is connectivity between the routers. Start the troubleshooting process at the physical or data link layer. Confirm connectivity and begin testing the TCP/IP-related functions at next layer up in the OSI model, the network layer.