HP 480 manual Basic Troubleshooting Tips, N o t e N o t e

N o t e

N o t e

Troubleshooting

Basic Troubleshooting Tips

Basic Troubleshooting Tips

Some of the router’s console commands are used for the troubleshooting instructions in this chapter. Refer to “Connect a console” (page 1-10) for details on connecting to the console port. For information on the Configuration Editor and the Network Command Language Interpreter (NCL), refer to the User’s Guide for your router.

Make sure that you have a valid network topology. If you have trouble after a recent change to the network, switch back to the previous topology. If you no longer have trouble, the new topology is probably at fault.

Make sure that the router is plugged in and that cable connections are secure.

If the console port does not work, refer to “Connect a console” (page 1-10), and then check “Troubleshooting a Terminal or Modem Connection” (page 3-12).

Check LEDs. For descriptions, see “Interpreting Back-Panel LEDs” (page 2-6). LED patterns that indicate a router or network error are shown in tables 3-1 and 3-2 (pages 3-2 through 3-4).

This chapter describes basic troubleshooting for hardware problems indicated by the Power, Self-test, Fault, and Net Fail LEDs appearing on all routers described in this manual. For the operating diagnosis indicated by other LEDs on a router, refer to “Meanings of Port Status LEDs” (page 2-9).

Troubleshooting 3

3-3