Specifications

Operations Manual

A port enters the blocking state because it has received information that

another bridge is the designated bridge for the LAN to which the port is

attached.

❑ Blocking indicates a port that is NOT PARTICIPATING in

forwarding frames thusly preventing the creation of multiple topology

paths. Received frames are discarded and frames are not submitted

for transmission. Station locations are not added to the database.

❑ Listening A port in this state is PREPARING TO PARTICIPATE

in frame relay but is temporarily disabled to prevent temporary loops.

Learning is disabled since changes in the active topology may lead to

incorrect information when the active topology becomes stable.

Received frames are discarded and frames are not submitted for

transmission. Station location information is not added to the

database.

❑ Learning indicates a port is PREPARING TO PARTICIPATE in

frame relay but it is temporarily disabled in order to prevent

temporary loops. Learning is enabled to allow information to be

acquired prior to frame relay in order to reduce the number of frames

unnecessarily relayed.

Received frames are discarded and frames are not submitted for

transmission. Station location information is added to the database.

❑ Forwarding indicates a port that is PARTICIPATING in frame

relay. It is both forwarding and submitting frames. The learning

process incorporates station location information into the filtering

database.

Received BPDUs will be submitted for transmission. They will also be

processed as required by the STP algorithm.

NOTE

With Release 2.4, a modification was made to the display of the Spanning Tree

ATM “PORT” forwarding state column of Omega to reflect the “link state” of

the port. If an ELAN is not in the ACTIVE state, the column now displays

“DISABLED” in the Forwarding State Column. Additionally, the spanning

tree “engine” is notified that the port is enabled or disabled when the ELAN

goes up and down.

Disabled. Disabled indicates a port that is NOT PARTICIPATING in

transmissions. Nor is it participating in the operation of the STP algorithm

and protocol.

Received frames are discarded. Submitted frames are not forwarded for

transmission.

Disabled is left when the port is enabled by management action and the

blocking state is entered.