Troubleshooting893-00992-E 4-5Port Connection ProblemsPort connection problems can usually be traced to a poor cable connection or animproper connection of the port cables at either end of the link. These types ofproblems can be remedied by making sure that the cable connections are secureand that the cables are connected to the correct ports at both ends of the link.Port connection problems can also be traced to the autonegotiation mode or theport interface.Autonegotiation ModesPort connection problems can occur when a port (or station) is connected toanother port (or station) that is not operating in a compatible mode (for example,connecting a full-duplex port on one station to a half-duplex port on anotherstation).The BayStack 350 switch negotiates port speeds according to the IEEE 802.3uautonegotiating standard. The switch adjusts (autonegotiates) its port speed andduplex mode to match the best service provided by the connected station, up to100 Mb/s in full-duplex mode.• If the connected station uses a form of autonegotiation that is not compatiblewith the IEEE 802.3u autonegotiating standard, the BayStack 350 switchcannot negotiate a compatible mode for correct operation.• If the autonegotiation feature is not present or is not enabled at the connectedstation, the BayStack 350 switch may not be able to determine the correctduplex mode.The Diagnostics LED isoff.A fatal error was detected bythe self-test.Cycle the power to the switch (disconnect andthen reconnect the AC power cord).If the problem persists, replace the switch.The Diagnostics LED isblinking.A nonfatal error occurredduring the self-test.Cycle the power to the switch (disconnect andthen reconnect the AC power cord).If the problem persists, contact the NortelNetworks Technical Solutions Center.Table 4-2. Corrective actions (continued)Symptom Probable cause Corrective action
