The All-New Switch Book: The Complete Guide to LAN Switching Technology, Second Edition

16.6. Wrap Up

So, there it is. This chapter should help you get started when troubleshooting issues arise in the switched environment. Of course, there are other techniques and more advanced applications that you may be involved in troubleshooting, but the methods discussed in this chapter should be used to assist in getting through the first two layers when running down an issue.

Make sure to check with your specific vendors for any tools or suggestions they may have when dealing with their equipment. Making the information available to others that you gather ahead of time really can help in times of crises.

Table 16.3. Our Top-Ten List of Data Link Issues

PROBLEM	POSSIBLE REASON	SOLUTION
Power LED is off	No power.	Check to see if the power cord is plugged in. If the power is off on a component card, ensure that the card is inserted completely.
	Blown fuse.	Replace the fuse. Replace the failed component. Replace the bridge.
Test LED is on.	The bridge has a hardware or software failure.	Review log files for any errors. Replace component and/or bridge
Link LED is not lit.	Bridge is not receiving any signals from the opposite end.	Check cable; replace if necessary. Verify configuration on both ends of the link. Check log files for errors on both ends.
Activity LED off.	Bridge is not receiving or sending data.	This may be normal if there is no data being passed. Verify configuration on both ends of the link. Check log files for errors on both ends.
Bridge is receiving a lot of late	There is most likely ...