3Com Hub 1000 SX 6 Uplink Connection to a 10/100 Mbps Switch, 2 Troubleshooting Tips, Symptom

3-6CHAPTER 3: MAKING CONNECTIONS

The Hub 1000 SX itself can be used as the network backbone by connecting the uplink to a server equipped with a 3C985-SX Gigabit EtherLink Server NIC or to a 10/100 Mbps switch equipped with a 3C16925 uplink device (see Figure 3-6). For these backbone connections, reconfigure the uplink for asymmetric flow control, as described in “Configuring Port Settings” in Appendix A.

Single-mode fiber-optic cable

Maximum distance: 3 km

SuperStack II	10/100 Mbps switch
Hub 1000 SX	with 3C16925 uplink device

Figure 3-6Uplink Connection to a 10/100 Mbps Switch

Troubleshooting Table 3-2 summarizes some common problems and their solutions.

Table 3-2Troubleshooting Tips

Symptom Explanation Solution

LINK LED does not light on a port.

ACTIVITY LED does not light on a port.

There is no link connection.

The port is not receiving data.

You may be attempting to connect to equipment that does not comply with Gigabit Ethernet standards or does not support auto-negotiation. Or, the link may be physically damaged (for example, the cable may be damaged).

Disable auto-negotiation on the port (see Appendix A). Configure the other end of the link for forced configuration (see the configuration guidelines for the device on the other end of the link). A restored connection rules out physical damage.

Make sure that the link is connected at both ends.

OVERTEMP LED is lit.	The unit has overheated.	Return the unit to the supplier.
	The fan may have failed.
Amber UNIT STATUS LED stays	POST software may	Use the command line interface (CLI) to confirm the
lit longer than 30 seconds.	be corrupted.	POST error. (See Appendix A.) If POST reports errors,
		return the unit to the supplier.

PAUSE LED remains lit.	A flickering PAUSE LED
	indicates normal flow control.
	A PAUSE LED that remains lit
	indicates that there is too
	much traffic.

Check for problems with the device attached to the Hub 1000 SX uplink.

POST FAIL messages appear	There is a fatal	Return the unit to the supplier.
in the CLI.	hardware error.