Cisco Systems ME 4924-10GE manual Diagnosing Problems, Symptom Possible Cause Resolution

Chapter 4 Troubleshooting

Diagnosing Problems

Diagnosing Problems

Common switch problems fall into these categories:

•Poor performance

•No connectivity

•Corrupted software

Table 4-1describes how to detect and resolve these problems.

		Table 4-1	Common Problems and Solutions
		Symptom		Possible Cause	Resolution
		Poor performance or excessive		Duplex autonegotiation mismatch.	Refer to the switch software
		errors			configuration guide for
					information on identifying
					autonegotiation mismatches.
				Cabling distance exceeded
				• Port statistics show excessive	• Refer to the switch software
				frame check sequence (FCS),	configuration guide for
				late-collision, or alignment	information on displaying
				errors.	port statistics.
				• For SFP port connections:	• Refer to your SFP
				– The distance between the	documentation for cabling
					guidelines.
				SFP port and the attached
				device exceeds the SFP
				cabling guidelines.
				Bad adapter in attached device
				• Excessive errors found in port	• Run adapter card diagnostic
				statistics.	utility.
		No connectivity		Incorrect or bad cable
				These are results of no link at both
				ends:
				• A crossover cable was used	• For the correct pinouts and
				when a straight-through was	the proper application of
				required, or the reverse.	crossover vs.
					straight-through cables, see
					the “Identifying a
					Crossover Cable” section
					on page B-2.
				• The cable is wired incorrectly.	• Replace with a tested good
					cable.
				• A crossover or straight-through	• For 1000BASE-T
				cable is wired incorrectly.	connections, be sure to use
					a twisted four-pair,
					Category 5 cable.
	Cisco ME 4924-10GE Ethernet Switch Hardware Installation Guide
4-2					OL-10071-01