Figure 11 Root Bridge - Zte ZXR10 5900 Series User Manual

Chapter 6 STP Configuration
state after MAX_AGE time. Port in LOOP_INCONSISTENT state
won't transmit data. This will avoid looping.
Port root protection function provides a way to protect root switch.
Port Root
Protection
In switch environment, all switches which enable spanning-tree
Function
will take part in the election of root switch. Switch which has
the lowest priority will be root switch. After election, if one new
switch which has smaller priority than the root switch connects to
network, this new switch will replace the original root switch to
become new root switch. This results in calculating spanning tree
again and interrupting network for a while. The new spanning tree
may contain sub-optimum path and lower network performance.
Here, let's see how port root protection function solves this prob-
lem.
F 11 ROOT BRIDGE
IGURE
In Figure 11, switch A and switch B are both core switches and
switch A is a root switch. Switch C is a edge switch. Port of switch
C which connects to switch B is blocked. The flow of BPDU is as
direction of arrow.
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