Intel express 550t User Manual

500.bok : 50007    124  Fri Sep 11 14:52:16 1998

C   H   A   P   T   E   R   7

Explanation: There may be a loop in the network and Spanning
Tree is not enabled.
Action: Avoid loops, or alternatively, either enable STP on all the
ports (using

Device Setup

) or specific ports (using

Port

Setup

).

The most common
problems are cable
problems

A high percentage of faults are caused by cable faults such as loose
connections or inappropriately wired cables.

Spanning Tree topology
changes

When a change is detected in the Spanning Tree network, the devices
forming the Spanning Tree go into a learning state to determine the
optimal routes between network segments. During this learning state,
the switch will not forward data traffic.

This is a normal occurrence for Spanning tree devices and no reme-
dial action is required. However, if the switch goes into the learning
state too frequently, the Spanning Tree may be unstable and should
be examined and possibly reconfigured.

To troubleshoot
communications problems

If the

POWER

 LED and the

STATUS

 LED are both on, but one or more

of the port

STATUS

 LEDs are off, then:

Reset the switch using the

Reset

 button.

Check the

STATUS

 LED for each switch port to which a cable is

attached.

VLANs

The use of VLAN policies can lead to unexpected communication
problems. If the policies are not designed with care, ports are not able
to reach network services. Check your VLAN policies and use the
VLAN monitoring to review the VLAN membership for that port or
address.