3Com XLPCI Troubleshooting Network Connection Problems, Eliminating Potential Causes of Problems

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TROUBLESHOOTING

C NETWORK CONNECTION

PROBLEMS

This appendix provides information about using a crossover cable to troubleshoot network problems when you know that the 3C900B NIC is working, but you cannot send or receive network traffic.

When you work with 10BASE-T cabling, concentrators, and NICs from different vendors, it is possible to connect everything but still have no communication between file servers and workstations. When there are several unknown variables, it is difficult to determine which component is failing.

Eliminating Potential Causes of Problems

Follow these steps to narrow the range of possible causes of some common problems:

1Determine whether your equipment complies with the 10BASE-T standard.

This is particularly important for data concentrators (hubs or repeaters).

2Connect a straight-through cable from the PC to the hub.

The hub performs an internal crossover so that the signal can go from TD+ to RD+ and TD– to RD–. When you look at an RJ-45 connector from the front (that is, the opposite side from where the wires enter the connector), pin 1 is identified on the right-hand side when the metal contacts are facing up.

3Make sure that the TD+ and TD– wires are twisted together, and that the RD+ and RD– wires are twisted together.

Using wires from opposing pairs can cause signals to be lost.

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Contents EtherLink XL PCI 10 Mbps Network Interface Cards User Guide 3Com Corporation 5400 Bayfront Plaza Santa Clara, California Contents Changing Configuration Settings Troubleshooting Network Connection Problems Page Figures Tables Finding Specific Information in This Guide About this GuideIf you are looking for Turn to Icon Description ConventionsConvention Description Bold-face typeNetwork Interface Card InstallingNIC Model Cable Connector Transceiver Network Segment Preparing for InstallationMaximum Inserting the NIC 2Installing the 3C900B NIC RJ-45 Port Connecting to the NetworkBNC Port 4Connecting to the BNC Port on the 3C900B-COMBO NICAUI Port 5Connecting to the AUI Port on the 3C900B-COMBO NICMeaning RJ-45 Interpreting the Link LEDState OffWindows Network DriverSpecified fields of the Identification tab screen, enter Windows 95 BuildClick Close Enter your user name and password, and then click OKClick Yes Insert EtherDisk diskette 2 in drive a and click Next Windows 95 OSR2Click Finish Windows 95 prompts you to reboot Windows NT Confirming InstallationClick the Adapters tab Windows NTClick Add 8CHAPTER 2 Installing the Network Driver Click Add Adapter Click Close Click OK in the Network Settings windowRunning AutoLink Software Novell NetWare Client DriverNetWare Novell NetWare Server DriverNetWare 4.10 Save and exit the file, and then reboot the serverMultiple NICs 3c90xcfg.exe Network Text File Name Network Driver Name Operating System Supported Network DriversRunning Diagnostic Programs Troubleshooting3Com NIC Diagnostics Program 3Com DOS Diagnostic ProgramRunning NIC Tests Double-click the 3Com icon in the Windows system tray13Com NIC Diagnostics General Screen Click the Diagnostics tabRunning the Echo Test Click StartOn the responding PC On both PCsOn the sending PC Close all open windows when the Echo test is finished 63Com NIC Diagnostics Support Screen 3Com Support ServicesClick the Support tab Accessing the Help SystemWindows 95 and Windows NT Removing NIC SoftwareQuestionAnswer Frequently Asked QuestionsQuestion Answer Make sure that your IP protocol does not compute the CRC Fast IP is designed to bypass the router, particularly where Page Option Default Setting Available Settings Changing Configuration SettingsRunning the 3Com NIC Diagnostics Program Using the DOS Configuration ProgramDisplaying Configuration Settings Running the 3Com NIC Diagnostics Program 33Com NIC Diagnostics Properties Screen Changing Configuration SettingsEnabling Pace Support 43Com DynamicAccess Setup ScreenPage Specifications SpecificationsCabling Requirements 10BASE-T Operation Twisted-Pair CableCategory Use 10BASE-T Specifications RJ-45 Connector Pin AssignmentsPage Fifo Packet Threshold Operational SettingsConcurrent UDP Streams Option Descriptions Disable Switch Packet PrioritizationLow-Priority Ratio Natural Packet IntervalDisable Receive Packet Buffering Changing Operational SettingsChanging Ranges and Protocols Eliminating Potential Causes of Problems Troubleshooting Network Connection ProblemsConnect a straight-through cable from the PC to the hub Crossover cable Troubleshooting Hubs with Crossover CableSupport from Your Network Supplier Online Technical ServicesAccess by Analog Modem 3Com Bulletin Board ServiceWorld Wide Web Site Access by Digital Modem 3ComFacts Automated Fax Service408 654 408 727Page Numbers IndexLANSRV.TXT 10BASE-TA-3 Page 3Com Corporation Limited Warranty FCC Class B Statement FCC Declaration of Conformity
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