346 | Multiple Spanning Tree Protocol (MSTP)
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To verify that EdgePort is enabled on a port, use the show config command from INTERFACE mode 
(Figure 19-9).
Figure 19-9.  Configuring EdgePort
Flush MAC Addresses after a Topology Change
FTOS has an optimized MAC address flush mechanism for RSTP, MSTP, and PVST+ that flushes 
addresses only when necessary, which allows for faster convergence during topology changes. However, to 
activate the flushing mechanism defined by 802.1Q-2003, use the 
tc-flush-standard command, which flushes 
MAC addresses after every topology change notification. To view the enable status of this feature, use the 
show running-config spanning-tree mstp command from EXEC Privilege mode.
MSTP Sample Configurations 
The running-configurations in Figure 19-11, Figure 19-12, and Figure 19-13 support the topology shown 
in Figure 19-10. The configurations are from FTOS systems. An MXL Switch system using FTOS, 
configured as shown in Figure 19-14, could be substituted for an FTOS router in this sample following 
topology and MSTP would function as designed.
FTOS Behavior: Regarding bpduguard shutdown-on-violation behavior:
 1 If the interface to be shutdown is a port channel, all the member ports are disabled in the hardware.
 2 When a physical port is added to a port channel already in error disable state, the new member port is also 
disabled in the hardware.
 3 When a physical port is removed from a port channel in error disable state, the error disabled state is 
cleared on this physical port (the physical port is enabled in the hardware).
 4 You can clear the error disabled state with any of the following methods:
•Perform a 
shutdown command on the interface.
•Disable the shutdown-on-violation command on the interface (use the no spanning-tree mstp edge-port 
[bpduguard | [shutdown-on-violation]]) command).
•Disable spanning tree on the interface (use the no spanning-tree command in INTERFACE mode).
 5 Disabling global spanning tree (use the no spanning-tree command in CONFIGURATION mode).
FTOS(conf-if-te-3/41)#spanning-tree mstp edge-port
FTOS(conf-if-te-3/41)#show config
!
interface TenGigabitEthernet 3/41
 no ip address
 switchport
 spanning-tree mstp edge-port
 spanning-tree MSTI 1 priority 144
 no shutdown
FTOS(conf-if-te-3/41)#