3Com 8 manual Problem Solving for the HUB 4 and 4C

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PROBLEM SOLVING FOR THE HUB 4 AND 4C

The OfficeConnect hub has been designed to aid you when detecting and solving possible problems with your network. These problems are rarely serious, the cause is usually a disconnected or damaged cable, or incorrect configuration. If this section does not solve your problem, contact your supplier for information on what to do next.

Perform these actions first:

Ensure all equipment is powered on.

Power off the hubs, wait about 5 seconds and then power on the hubs.

Check the following symptoms and solutions:

Power LED not lit. Check your power adapter connection. If there is still no power, you may have a faulty power adapter which needs replacing with another OfficeConnect power adapter. Do not use any other power adapter

with the hub.

Alert LED continuously lit. There is either continual excessive use of your network (over 80%) or, more likely, a 10BASE-T port has partitioned due to a loop in your network (in which case the corresponding Port Status LED will be yellow). Examine your connections and remove the loop. Each piece of equipment needs only one connection to your OfficeConnect hub.

Port Status LED yellow for a 10BASE-T port. It is likely that there is a loop in your network which has caused this port to partition. Examine your connections and remove the loop. Each piece of equipment needs only one connection to your OfficeConnect hub. The LED will change from yellow to green, on receiving a valid packet on the port.

Link between two OfficeConnect hubs not working. Check your hub connections; follow the information given for your hub. With 10BASE-T it is likely an Uplink/Normal switch is incorrectly set. With 10BASE-2 it is likely a terminator (end piece) is not properly fitted; this would cause the Coax Port Status LED to light yellow (partition).

AUI/COAX Port Status LED not lit when external transceiver in use. Check the AUI cable is correctly connected to the hub and to the external transceiver. Ensure both slide locks are engaged.

AUI/COAX Port Status LED yellow when the 10BASE-2 port is not being used. The port has partitioned. This is correct operation.

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Contents OfficeConnect Ethernet Hub 4, 4C, 8, 8C 3Com Corporation 5400 Bayfront Plaza Santa Clara, California Important Safety Information Wichtige Sicherheitshinweise Consignes importantes de sécurité Technical Support Introduction Transceiver Connections Creating Your NetworkWhat Else Do I Need? Workstation ConnectionsHub Connections 10BASE-2Twisted Pair TP Cables Stacking the Units Together Rubber FeetStacking Clip Using Your Hub Positioning Your HubSecuring Your Hub AUI/COAX Status LEDs Hub 4C only Officeconnect Ethernet HUB 4 and 4CEthernet Hub 4 and 4C-Front Network Utilization LEDs Hub 4C only10BASE-2 port Hub 4C only Ethernet Hub 4 and 4C-RearConnecting Workstations and Other Equipment to Your Hub Connecting OfficeConnect Ethernet Hubs TogetherConnecting Transceivers to the AUI Port Checking Connections Connecting Hubs Using 10BASE-2Spot Checks Connecting Hubs Using 10BASE-TProblem Solving for the HUB 4 and 4C Straight-through Cable/Crossover Cable Port Status LEDs Power LED Collision LEDOfficeconnect Ethernet HUB 8 and 8C Ethernet Hub 8 and 8C-FrontPower Adapter socket Uplink/Normal switch Ethernet Hub 8 and 8C-Rear10BASE-2 port Hub 8C only Connecting Workstations and Other Equipment to Your Hub 50 Ohm Terminator Switch set to Normal out Uplink Problem Solving for the HUB 8 and 8C Normal Pin Uplink Port Rx+ Tx+ Networking Terminology Standards Dimensions and StandardsDimensions and Operating Conditions Power WeightEnvironmental Statement about the Documentation Environmental StatementsEnd Of Life Statement Regulated Materials StatementImportant Safety Information Wichtige Sicherheitshinweise Consignes Importantes DE Sécurité World Wide Web Site Online Technical Services3Com Knowledgebase Web Services Technical SupportSupport from 3Com Support from Your Network SupplierCountry Telephone Number Asia, Pacific Rim EuropeEurope, South Africa, and Middle East North America Country Telephone Number Latin AmericaCountry Telephone Number Fax Number Returning Products for Repair3Com Corporation Limited Warranty Warranties Exclusive Disclaimer Electromagnetic Compatibility Wall mounting screw hole guide 150 mm 5.9 Part No. DUA 1670-0AAA04 Published June