Securing Spanning Tree
Spanning Tree tuning can help prevent a rogue device from becoming root
bridge or otherwise disrupting your user traffic. There are several tools at
your disposal—Figure 8-2 shows where each could be used in a switched
network.
Figure 8-2 Securing Spanning Tree
Blocking
Forwarding
PortFast,
BPDU Guard
RootGuard
UDLD UDLD
UDLD
UDLD
LoopGuard
RootGuard
LoopGuard
BPDU Filter
Root Bridge
UDLD
UDLD UDLD
UDLD