IBM 8239 Token-Ring Stackable Hub, Setup And User Manual

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Port Connection
When the beacon fault is determined to originate from one of the ports on the 8239,
the 8239:
¹
Isolates the port from the stack ring
¹
Sends a Port Down trap to indicate what port has been beacon-wrapped.
Refer to “Trap Processing” on page 7-10 for details about sending the trap.
¹
Sets the status of the port to BEACON WRAPPED and increments the counter
that indicates the number of times this port has been beacon-wrapped. The
port status and beacon counter value can be displayed by issuing the DISPLAY
PORT terminal interface command.
¹
Sets the port’s yellow status LED to on and sets the port’s green status LED
off.
Once a port is beacon-wrapped, the 8239 will automatically unwrap the port when
there is a recurrence of phantom at that port, as long as the port has not exceeded
the beacon threshold. Refer to “Beacon Threshold” on page 6-2 for more
information about the beacon threshold. When the number of times a port has been
beacon-wrapped exceeds the configured threshold value, the port is considered to
be permanently beacon-wrapped and the port status is set to
BCN_THRES_ERROR. In this state, the port’s yellow status LED blinks.
When a device that does not generate phantom voltage is attached to the port
(refer to “Port Concepts” on page 6-1) or when a port has been beacon-wrapped
due to exceeding the beacon threshold, manual intervention is required. After the
fault has been corrected, you must re-enable the port by issuing the ENABLE
PORT terminal interface command. This command sets the beacon counter for that
port to zero.
Management Interface (8239 Model 1 only)
When the beacon fault is determined to originate with the Management Interface,
the 8239 Model 1:
¹
Isolates the Management Interface from the stack ring.
¹
Indicates in the management_interface_status portion of the LCD that the
Management Interface was beacon-wrapped. Refer to “Operational Codes” on
page 5-15 for more information.
¹
Sets the adapter status of the Management Interface to BEACON WRAPPED
and increments the counter that indicates the number of times the Management
Interface has been beacon-wrapped. The Management Interface adapter status
and beacon counter value can be displayed by issuing the DISPLAY
MANAGEMENT_INTERFACE terminal interface command.
Once the Management Interface is beacon-wrapped, the 8239 will automatically
re-insert the Management Interface into the stack ring after the Management
Interface verifies that its transmit and receive paths are OK. The Management
Interface uses the beacon threshold value that is configured for the hub in the
same way that the ports do. The default value for the beacon threshold value is 8.
To display or change the beacon threshold value, issue the DISPLAY HUB or SET
HUB BEACON_THRESHOLD terminal interface commands, respectively. When the
number of times the Management Interface has been beacon wrapped exceeds the
configured threshold value, the Management Interface is considered to be
Chapter 6. Concentrator Functions
6-13