Allied Telesis AT-S63 - Manual (Page 538)

Chapter 22: Spanning Tree and Rapid Spanning Tree Protocols
538 Section V: Spanning Tree Protocols
4096, with 0 being the highest priority. For a list of the increments,
refer to Table 14, “Bridge Priority Value Increments” on page 519.
3 - 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.
4 - 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.
5 - 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.
When you select a value for maximum age, observe the following
rules:
MaxAge must be greater than (2 x (HelloTime + 1)).
MaxAge must be less than (2 x (ForwardingDelay - 1))
6 - Bridge Identifier
The bridge identifier of the switch. The identifier consists of the
switch’s bridge priority value and MAC address. The values are
separated by a slash (/). To change the switch’s priority value, use
option 2, Bridge Priority. The MAC address of the switch cannot be
changed.
7 - Root Bridge
The MAC address of the root bridge of the spanning tree domain. This
value cannot be changed and is only displayed when RSTP is
activated on the switch.
8 - Root Priority
The priority value on the root bridge of the spanning tree domain. This
parameter is only displayed when RSTP is enabled on the switch. To
change the priority value on the root bridge, you must start a
management session on the switch functioning as the root bridge and
change its bridge priority value.