|  | 8.12 | Troubleshooting the Network
| 8.12.5 | Given a network problem scenario, determine the problem
Use the following techniques to determine the problem: recognize abnormal physical conditions; isolate and correct problems where the fault is in the physical media (patch cable or cable run); check the status of servers; check for configuration problems with DNS, WINS, and HOST files; check for viruses; check the validity of the account name and password; recheck operator logon procedures; and select and run appropriate diagnostics. Question: What are some common issues to look for if a network is having problems? First, abnormal physical conditions should be considered, such as power interruptions, presence of high heat or humidity where a networking device is located, or large amounts of electrical noise. An extremely common problem, often referred to as a layer 1 problem, is somewhere in the conducting path from a PCs NIC to the nearest networking device (typically a hub or a switch). The patch cable from the PC to the outlet could be faulty: Bad terminations, bent or crushed cable, or improper wiring sequences. The horizontal cable run, from the outlet to the patch panel, could be bent, crushed, cut, improperly mounted, or otherwise damaged. Or the patch and jumper cables from the patch panel to the networking device could be the incorrect type of cable or also have damage. Servers should be checked to verify that all servers and resources are functioning properly. Servers and resources such as DNS, WINS, and HOST files should be checked for proper configuration. A virus scan can be done to be sure that a virus has not tapped into the networking causing problems. Workstations must have all of the proper settings. Next, verify the validity of the user's account and password. Is the user typing in the correct user id and password? Does the individual have access? Verify the log in procedures. Finally, if the problem can not be resolved, vendor provided diagnostics should be run.