Does the failure symptom appear to be related to a specific MAU or
hub port failure? Go
to page 4.1.
Do the failure symptoms that appear to be related to a suspected
bad MAU or wiring hub module occur with multiple users or the complete
Token Ring network?
to page 4.2.
Because this procedure is
generic as to the MAU and wiring hub manufacturer, for some of the
troubleshooting steps mentioned on this page, you should also reference
the respective manufacturer's documentation for any special predefined
methods for checking configuration and for diagnostic testing.
In the case of some wiring
hubs, you may have certain diagnostics available that can help you
locate a specific problem. If this type of diagnostics is available,
attempt to use it for fault isolation.
4.1 A specific
MAU or hub port appears to be encountering a failure.
Move the lobe cable from the suspected bad port to another port on the
same MAU or wiring hub module. Before you move the lobe cable, make sure
the new port is functioning. Next, retest the respective ring station or
network peripheral on the new MAU or wiring hub port.
Did physically changing the port get rid of the failure symptom?
The suspected bad port is bad.
Replace the respective MAU or hub module and retest the ring station or
network peripheral for proper operation. If the failure symptom is gone,
record the problem in the network maintenance and service log. If problems
still exist, go to the next step .
If a failure still exists with
the same ring station or network peripheral, re-attach the lobe cable to
the original port and troubleshoot the respective lobe area for the assigned
MAU or wiring hub port by going to page 2.
4.2 A suspected
bad MAU or wiring hub module appears to be causing failure symptoms with
multiple users or the complete Token Ring network.
Whether the failure symptom is solid or intermittent, remove the suspected
bad MAU or wiring hub module and associated main ring path cabling sections
from the ring configuration and then retest the ring.
Are the failure symptoms now gone?
The respective MAU, wiring hub
module, or a main ring path cabling section is at failure. Replace the
removed unit and cables with another unit and cables. Retest the new ring
configuration. If no problems are encountered, record the problem in the
network maintenance and service log. If problems still exist, go to the
Even if your problem is now
fixed, if you feel that one of the main ring path cabling sections did
cause the problem, you can verify the problem by going to page 3. If you
want to verify the MAU or wiring hub failure, you can do so with any available
If failure symptoms still exist,
reinsert the original MAU or wiring hub module and respective cables into
the ring configuration.
Have you troubleshot and verified the integrity of the main ring
a protocol analysis session to gain more conclusive fault isolation data
by going to page 15.
the main ring path cabling by going to page 3.
November 15, 1996