Cisco Systems 3012, 3110X Verify Switch Module Connections, Bad or Damaged Cable, Link Status

Chapter 3 Troubleshooting

Diagnosing Problems

Verify Switch Module Connections

Review this section when troubleshooting switch module connection problems.

Bad or Damaged Cable

Always evaluate the cable for marginal damage or failure. A cable might be just good enough to connect at the physical layer, but it could corrupt packets as a result of subtle damage to the wiring or connectors. You can identify this situation because the port has many packet errors or the port constantly flaps (loses and regains link). You should:

•Inspect or exchange the copper or fiber-optic cable with a known, good cable.

•Look for broken or missing pins on cable connectors.

•Rule out any bad patch panel connections or media convertors between the source and destination. If possible, bypass the patch panel or eliminate faulty media convertors (fiber-optic-to-copper).

•Try the cable in another port or interface, if possible, to see if the problem follows the cable.

•StackWise Plus cable: remove and inspect the cable and StackWise Plus port for bent pins or damaged connectors. If the StackWise Plus cable is bad, replace it with a known good cable.

Ethernet and Fiber Cables

Make sure that you have the correct cable type for the connection:

•For Ethernet, use Category 3 copper cable for 10 Mb/s UTP connections. Use Category 5, Category 5e, or Category 6 UTP for 10/100 or 10/100/1000 Mb/s connections.

•For fiber-optic connectors, verify that you have the correct cable for the distance and port type. Make sure that the connected device ports both match and use the same type encoding, optical frequency, and fiber type. For more information about cabling, see the “10-Gigabit Ethernet X2 Transceiver Module Cable Specifications” section on page B-3.

•For copper connections, determine if a crossover cable was used when a straight-through was required or the reverse. Enable auto-MDIX on the switch module, or replace the cable. See Table 2-1for recommended Ethernet cables.

Link Status

Verify that both sides have link. A single broken wire or one shutdown port can cause one side to show link, but the other side does not have link.

A link LED does not guarantee that the cable is fully functional. The cable might have encountered physical stress that causes it to function at a marginal level. If the link light for the port does not come on:

•Connect the cable from the switch module to a known good device.

•Make sure that both ends of the cable are connected to the correct ports.

•Verify that both devices have power.

•Verify that you are using the correct cable type. See Appendix B, “Connector and Cable Specifications” for more information.

•Look for loose connections. Sometimes a cable appears to be seated, but is not. Disconnect the cable, and then reconnect it.

Catalyst Switch Module 3110G, 3110X, and 3012 for IBM BladeCenter Hardware Installation Guide

3-2 OL-12192-01