3Com 3CR16709-91 manual Solving Hardware, Problems, Refer to the list of suggested solutions below

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Solving Hardware Problems

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■The quality of cable is satisfactory.

■Auto-negotiation settings are the same at both ends.

Auto-negotiation problems will occur with 10BASE-T, 100BASE-TX or 1000BASE-T where auto-negotiation is disabled and incorrect cables are being used (cross-over or straight).

Auto-negotiation problems will occur with fiber if:

■Fibers are broken.

■Auto-negotiation differs at either end (a link appears at the ‘fixed’ end and not at the auto-negotiation end).

A PoE device is connected and yet the PoE Status LED does not light

Refer to “A device is connected to the Switch but power is not being supplied” on page 53 for troubleshooting procedures.

Solving Hardware	In the rare event of your Switch unit experiencing a hardware failure,
Problems	refer to the list of suggested solutions below.

A device is connected to the Switch but power is not being supplied

If power is not being supplied to a device connected to the Switch, you should do the following checks:

■Check that the device is compliant with the 802.3af standard ref. [18].

The Switch will only supply power through rear panel ports 1, 2, 5, and 6 to 802.3af compliant devices.

■Check that the power budget for the Switch has not been exceeded.

If the power budget has been exceeded, then by default, the powered device connected to the Power over Ethernet port with the lowest priority port will lose power. However, if all the devices connected to the Switch have equal priority levels, then the port with the highest number will lose power.

By default the Switch will allow a device to receive power as long as the Power over Ethernet power supply has 18 watts spare in its power budget. If this much power is not available the device will not be powered (unless it has a higher priority than existing powered ports) and a Power over Ethernet fault will be reported for that port. If

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Contents 3CR16708-91 3CR16709-91 United States Government Legend 3Com Corporation Campus Drive Marlborough, MA USAContents Setting UP for Management Outs Problem SolvingPage About this Guide Convention Description ConventionsIcon Description Documentation RelatedDocumentation Pddtechpubscomments@3com.com CommentsIntroducing Hardware Features Switch Alert LED Power LED Port Status Leds PoE Status Leds Switch Front View DetailColor Indicates 10BASE-T/100BASE-TX Port Status LEDs SFP Module Status LED Switch 9 FX only100BASE-FX Port Status LEDs Switch 9 FX only Alert LED LEDSwitch 9 rear view Switch Rear View DetailSwitch Rear View Detail Page Default Settings shows the default settings for the Switch Page Installing the Switch Site Package ContentsChoosing a Suitable Air temperature around the Switch does not exceed 50 C 122 F Upwards Wall-mountingMounting Instructions for Cement WallsMake two holes 150 mm 5.9 in. apart Instructions for Wood WallsColor State Power and Alert LED colorsPower-up Sequence Cross-over Cable Straight-through Cable SFP Operation Installing the Switch Inserting a SFP Transceiver Installing the Switch Setting UP for Management Configure IP information manually for your Switch or view Setting UpAutomatically configured IP information OverviewAutomatic IP Configuration Manual IP ConfigurationSetting UP for Management Pre-requisites Manually Configuring IP InformationConnecting a workstation to the Switch via the console port Connecting the Workstation to the SwitchExample top-level command line interface menu Setting Up the Switch with IP InformationAutomatically Configured IPViewing Viewing Automatically Configured IP Information Viewing IP Information via the Console Port Methods of Managing a Switch Refer to Setting Up Web Interface Management on Refer to Setting Up Command Line Interface Management onNetwork Using Telnet Command LineInterface Management CLI Management viaChoosing a Browser Setting Up WebInterface Management Protocol Snmp can manage a Switch if Setting Up SnmpOver the Network Management workstationUser Default Name Password Access Level Default UsersDefault Users and Passwords Setting UP for Management Problem Solving Indicated by LEDs Solving ProblemsSolving Hardware ProblemsRefer to the list of suggested solutions below How do you obtain a registered IP Address? Solving Communication ProblemsIP Addressing Solving Software Upgrade Problems Problem Solving Safety Information This must be approved for the country where it is used Power Cord Set Japan Important Safety InformationImportant Safety Information Schko ’information de Sécurité Importante’information de Sécurité Importante Vorsicht Europe Wichtige SicherheitsinformationenInformación de seguridad importante Schuko Dispositivo Láser DE Clase CSA Importanti Informazioni di SicurezzaAvvertenza porte a fibre ottiche Protezione degli occhi Appendix a Safety Information RJ-45 to RS-232 RJ-45 Pin Signal DB-9 Pin DirectionAdapter Cable Panel. The pinout is shown belowRJ-45 Pin ConnectorsAssignments Pin NumberOfficeConnect Managed Switch 9 and Switch 9 FX Terminal Emulation Protocols Used for AdministrationStandards Supported Register Your ServicesProduct PurchaseTroubleshoot Access SoftwareOnline DownloadsContact Us US and Canada Telephone Technical Support and Repair Country Telephone NumberLatin America Telephone Technical Support and Repair Index Snmp Regulatory Notices