Upgrading and Repairing Networks (5th Edition)

You troubleshoot a switch just like you troubleshoot a hub. If the switch has a link light (or LED), be sure it's on, indicating that the port is operating as it should and receiving a signal from the network adapter attached to the client computer (or another switch, as the case might be). Management software for the switch can be based on the SNMP or RMON specifications, or it might be proprietary in nature. In either case, all but the low-end home-office switches provide the capability to examine, test, and set parameters for each port on the switch.

For example, if you have a client computer connected to the switch, and the client's network adapter is autosensing, meaning that it can determine the network speed, it might not be compatible with the autosensing functionality of the switch. In that case, you might have to manually configure the switch port to match the higher speed that the network adapter can support or manually configure the network adapter to run at the switch's speed and duplex mode.

For more information about troubleshooting switches using SNMP and RMON, see Chapter 49, "Network Testing and Analysis Tools."