D-Link DES-3624 - Switch - Stackable User manual - Sta Operation Levels
Stackable NWay Ethernet Switch User’s Guide
will be automatically activated, and STA will
automatically re-configure the network topology.
STA Operation Levels
STA operates on two levels: the bridge level and the port level.
On the bridge level, STA calculates the Bridge Identifier for
each Switch, then sets the Root Bridge and the Designated
Bridges. On the port level, STA sets the Root Port and
Designated Ports. Details are as follows:
On the Bridge Level
♦ Root Bridge The switch with the lowest Bridge Identifier
is the Root Bridge. Naturally, you will want the Root
Bridge to be the best switch among the switches in the
loop to ensure the highest network performance and
reliability.
♦ Bridge Identifier This is the combination of the Bridge
Priority (a parameter that you can set) and the MAC
address of the switch. Example: 4 00 80 C8 00 01 00,
where 4 is the Bridge Priority. A lower Bridge Identifier
results in a higher priority for the switch, and thus
increases it probably of being selected as the Root Bridge.
♦ Designated Bridge From each LAN segment, the
attached Bridge that has the lowest Root Path Cost to the
Root Bridge is the Designated Bridge. It forwards data
packets for that LAN segment. In cases where all
Switches have the same Root Path Cost, the switch with
the lowest Bridge Identifier becomes the Designated
Bridge.
♦ Root Path Cost The Root Path Cost of a switch is the
sum of the Path Cost of the Root Port and the Root Path
Switch Management Concepts
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