Allied Telesis AT-GS950/24 - Manual (Page 73)

AT-GS950/24 Web Interface User Guide
73
Bridge Priority
and the Root
Bridge
The first task that bridges perform when a spanning tree protocol is
activated on a network is the selection of a root bridge. A root bridge
distributes network topology information to the other network bridges and
is used by the other bridges to determine if there are redundant paths in
the network.
A root bridge is selected by the bridge priority number, also referred to as
the bridge identifier, and sometimes the bridge’s MAC address. The bridge
with the lowest bridge priority number in the network is selected as the root
bridge. If two or more bridges have the same lowest bridge priority
number, the one with the lowest MAC address is designated as the root
bridge.
You can change the bridge priority number in the AT-S115 Management
software. You can designate which switch on your network is the root
bridge by giving it the lowest bridge priority number. You may also
consider which bridge should function as the backup root bridge in the
event you need to take the primary root bridge off line and assign that
bridge the second lowest bridge identifier number.
The bridge priority has a range of 0 to 61440 in increments of 4096. To
make this easier for you, the AT-S115 Management software divides the
range into increments. You specify the increment that represents the
desired bridge priority value. The range is divided into the following sixteen
increments:
 0
 4096
 8192
 12288
 16384
 20480
 24576
 28672
 32768
 36864
 40960
 45056
 49152
 53248
 57344
 61440