Dell Force10 E600i FTOS Version 8.4.1.5 Configuration Guide for ExaScale - Page 626

www.dell.com | support.dell.com 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, you may activate the flushing mechanism defined by 802.1Q-2003 using the command tc-flush-standard, which flushes MAC addresses upon every topology change notification. View the enable status of this feature using the command show running-config spanning-tree mstp from EXEC Privilege mode. Displaying STP Guard Configuration To verify the STP guard configured on MSTP interfaces, enter the show spanning-tree msti [instance-number] guard command. Refer to the Spanning Tree Protocol chapter for information on how to configure and use the STP root guard, loop guard, and BPDU guard features. The following text shows an example for instance 5 in an MSTP network in which: • Root guard is enabled on a port that is in a root-inconsistent state. • Loop guard is enabled on a port that is in a forwarding state. • BPDU guard is enabled on a port that is shut down. FTOS#show spanning-tree msti 5 guard Interface Name Instance Sts Guard type Gi 0/1 5 INCON(Root) Root Gi 0/2 5 FWD Loop Gi 0/3 5 EDS(shut) Bpdu MSTP Sample Configurations The running-configurations in the following examples support the topology shown in Figure 32-2. The configurations are from FTOS systems. An S50 system using SFTOS, configured as shown in the final example, could be substituted for an FTOS router in this sample following topology and MSTP would function as designed. Figure 32-2. MSTP with Three VLANs Mapped to Two Spanning Tree Instances R1 R2 1/2 Forwarding 2/1 root 1/3 2/3 Blocking 3/1 3/2 R3 626 | Multiple Spanning Tree Protocol