Dell MX9116n EMC SmartFabric OS10 User Guide - Page 444

spanning-tree rstp priority Sets the priority value for RSTP. Syntax spanning-tree rspt priority priority value Parameters priority priority value - Enter a bridge-priority value in increments of 4096, from 0 to 61440. Valid priority values are: 0, 4096, 8192, 12288, 16384, 20480, 24576, 28672, 32768, 36864, 40960, 45056, 49152, 53248, 57344, and 61440. All other values are rejected. Default Not configured Command Mode CONFIGURATION Usage Information RSTP determines the root bridge but you can assign one bridge a lower priority to increase the probability of it being the root bridge. A lower priority value increases the probability of the bridge becoming a root bridge. Example OS10(config)# spanning-tree rstp priority 5002 Supported Releases 10.2.0E or later Multiple Spanning-Tree MSTP is one of the variations of the rapid spanning-tree protocol that mitigates some of the challenges of RPVST+. RPVST+ allows a spanning-tree instance for each VLAN. This 1:1 approach is not suitable if you have multiple VLANs - each spanning-tree instance costs bandwidth and processing resources. You can configure Multiple Spanning-Tree Instances (MSTIs) and map multiple VLANs to one spanning-tree instance to reduce the total number of instances. For more information on RPVST+, see RPVST+. When you enable MST, all ports in Layer 2 (L2) mode participate in MST. OS10 only supports one MST region. You can achieve load balancing using the MST protocol (MSTP). For example, as shown in the following figure, when you map three VLANs to two multiple spanning-tree instances (MSTIs), VLAN 100 traffic takes a different path than VLAN 200 and 300 traffic. Configuring MST is a four-step process: 1. Enable MST, if the current running spanning-tree protocol (STP) version is not MST. 2. (Optional) Map the VLAN to different instances in such a way that the traffic is load balanced well and the link utilization is efficient. 3. Ensure the same region name is configured in all the bridges running MST. 4. (Optional) Configure the revision number. The revision number is the same on all the bridges. Configure MSTP When you enable MST globally, all switch ports, port-channels, and VLAN interfaces get automatically assigned to MSTI zero (0). In a MSTI, only one path is enabled for forwarding. • Enable MST in CONFIGURATION mode. spanning-tree mode mst 444 Layer 2