Brocade FastIron Ethernet Switch Platform and Layer 2 Switching Configuration Guide User Manual
Page 211
Example 1: Configure the Per-VLAN Spanning Tree on the MCT Clients
External connections between clients other than the links in an MCT cluster can cause Layer 2 loops.
Use Spanning Tree on the MCT clients so that the MCT cluster forwards Spanning Tree Bridge Protocol
Data Units (BPDU) as if the cluster were in a pass-through mode.
Configure per-VLAN Spanning Tree on the two MCT VLANS 1901 and 1905 to have Rapid Spanning
Tree (RSTP/802.1w). This example is based on the network topology shown in
Client-1 Configuration
Client-1(config)# vlan 1901 1905
Client-1(config-mvlan-1901*1905)# spanning-tree 802-1w
Client-1(config-mvlan-1901*1905)# end
Client-2 Configuration
Client-2(config)# vlan 1901
Client-2(config-vlan-1901)# spanning-tree 802-1w
Client-2(config-vlan-1901)# spanning-tree 802-1w priority 4095
Client-2(config-vlan-1901)# vlan 1905
Client-2(config-vlan-1901)# spanning-tree 802-1w
Client-2(config-vlan-1901)# end
The MCT cluster switches do not have the spanning tree configured, but the BPDUs are passed
through, and the Spanning Tree on the clients converges.
Use the show 802-1w vlan command to display the RSTP information for the specified port-based
VLAN.
Example 2: Configure Single Spanning Tree (SSTP) on the MCT Clients
In a network where MCT clients have Single 802.1d or Single 802-1w elements of the Spanning Tree
protocol enabled, configure the central processing unit (CPU) of the MCT peer switches so that it
performs BPDU forwarding to avoid Layer 2 loops.
Using SSTP on MCT clients allows you to run a separate spanning tree on each port-based VLAN,
which you can enable or disable on an individual basis. As an alternative, you can run a single spanning
tree across all ports and VLANs on the device.
Enabling BDPU flooding can increase the CPU usage. When BPDU flooding is enabled, do not create
redundant links between the MCT cluster devices or cascade multiple MCT clusters.
To enable the CPU to perform BPDU forwarding, use the bpdu-flood-enable command. This example is
based on the network topology shown in
on page 209.
Router-1 configuration
Router-1(config)# bpdu-flood-enable
Warning - Any recieved untagged BPDUs will now be flooded to all the ports.
Router-2 configuration
Router-2(config)# bpdu-flood-enable
Warning - Any recieved untagged BPDUs will now be flooded to all the ports.
Example 1: Configure the Per-VLAN Spanning Tree on the MCT Clients
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