Planet WGSW-2840 User Manual page 36

B
Port 1
Bridge ID = 30
Port 2
Portcast = 19
LAN 2
In this example, only the default STP values are used.
B
Port 1
Port 2
LAN 2
The switch with the lowest Bridge ID (switch C) was elected the root bridge, and the ports were selected
to give a high port cost between switches B and C. The two (optional) Gigabit ports (default port cost = 4)
on switch A are connected to one (optional) Gigabit port on both switch B and C. The redundant link
LAN 1
A
Port 3
Bridge ID = 15
Port 1
Portcast = 4
Portcast = 4
Port 3 Portcast = 19
Before Applying the STA Rules
LAN 1
A
Port 3
Root Bridge
Port 1
Designated Port
Root Port
Blocked
Port 3
After Applying the STA Rules
Portcast = 19
Port 2
Portcast = 4
Portcast = 4
C
Bridge ID = 20
Port 2
Port 2
Designated Port
Root Port
C
Designated Bridge
Port 2
Port 1
Port 3
Portcast = 19
LAN 3
Port 1
Port 3
LAN 3