Entries will remain in ARP cache for 10 minutes on windows NT Can use this command if you suspect invalid ARP entries in ARP cache. When troubleshooting a network, first set the priority of the problem. Second ask questions. Determine possible causes and try to isolate the problem. Make one change at a time.
Most problems happend at the physycal layer.
The problem can be as simple as a loose patch cable. After you have solved the problem, try to connect to the network and transfer a file. Then document the problem and the solution. Allways keep good documentation of your network. The following tools can be used for network troubleshooting Tool Discription Digital Voltmeter Simple inexpensive tool.