Allied Telesis AT-S62 - Manual (Page 250)

Chapter 20: STP, RSTP, and MSTP
Section IV: Spanning Tree Protocols 250
2. Adjust the STP bridge settings as needed. The parameters are
described below.
Bridge Priority
The priority number for the bridge. This number is used in
determining the root bridge for RSTP. The bridge with the lowest
priority number is selected as the root bridge. If two or more
bridges have the same priority value, the bridge with the
numerically lowest MAC address becomes the root bridge. When
a root bridge goes off-line, the bridge with the next priority
number automatically takes over as the root bridge.
This parameter can be from 0 (zero) to 61,440 in increments of
4096, with 0 being the highest priority. There are sixteen
increments. You specify the increment representing the desired
bridge priority value. The increments are shown in Table 6.
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 Delay
The waiting period in seconds 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, resulting in network loops.
The range is 4 to 30 seconds. The default is 15 seconds.
Table 6 Bridge Priority Value Increments
Increment
Bridge
Priority
Increment
Bridge
Priority
0 0 8 32768
1 4096 9 36864
2 8192 10 40960
3 12288 11 45056
4 16384 12 49152
5 20480 13 53248
6 24576 14 57344
7 28672 15 61440