Allied Telesis AT-S63 - Manual (Page 176)

Chapter 14: STP and RSTP
176 Section II: Advanced Features
Bridge Hello Time
The time interval between generating and sending configuration
messages by the bridge. This parameter can be from 1 to 10
seconds. The default is 2 seconds.
Bridge Forwarding
The waiting period before a bridge changes to a new state, for
example, becomes the new root bridge after the topology
changes. If the bridge transitions too soon, not all links may have
yet adapted to the change, possibly resulting in a network loop.
The range is 4 to 30 seconds. The default is 15 seconds. This setting
applies only to ports running in the STP-compatible mode.
Bridge Max Age
The length of time after which stored bridge protocol data units
(BPDUs) are deleted by the bridge. All bridges in a bridged LAN use
this aging time to test the age of stored configuration messages
called bridge protocol data units (BPDUs). For example, if you use
the default 20, all bridges delete current configuration messages
after 20 seconds. This parameter can be from 6 to 40 seconds. The
default is 20 seconds.
In selecting a value for maximum age, the following must be
observed:
MaxAge must be greater than (2 x (HelloTime + 1)).
MaxAge must be less than (2 x (ForwardingDelay - 1))
Bridge Identifier
The MAC address of the bridge. The bridge identifier is used as a
tie breaker in the selection of the root bridge when two or more
bridges have the same bridge priority value. This value cannot be
changed.
6. After you have made your changes, click Apply.
7. To adjust RSTP port settings, click on the port in the switch image and
click Modify. You can select more than one port at a time.