Руководство По Проектированию для Cisco Cisco Nexus 5010 Switch
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Configuration Steps
Spanning Tree Configuration
Regardless of whether you are using Rapid PVST+ or MST, make sure to configure spanning tree to use pathcost
method long, as follows:
spanning-tree pathcost method long
Configuring Rapid PVST+ follows usual well-known guidelines. In addition to these guidelines, if you configure
MST, you will have to follow a configuration similar to the following (and with different priorities on primary and
secondary root):
spanning-tree mode mst
spanning-tree mst 0-1 priority 24576
spanning-tree mst configuration
name dc1
revision 1
instance 1 vlan 1-3967,4048-4093
If you are using MST, remember to configure the region mapping for all 4000 VLANs, even if you are not using
them all. Doing so uses no hardware or CPU resources until the VLAN is created and assigned to interfaces. But
because in MST changing the region configuration can cause a temporary glitch, you should plan the MST region
at the deployment time. And you should create VLANs and decide where to trunk them whenever a new VLAN
needs to be provisioned (see Chapter 4 in this design guide for more information). If you follow this approach, there
is no spanning-tree reconvergence when you need to provision a new VLAN.
Remember to ensure that if you are using MST, the region configuration for primary and secondary vPC peers
matches.
Note: If the topology includes other switches that are not based on Cisco NX-OS Software, make sure to
change the MST region mappings on the adjacent switches to match the Cisco NX-OS Software range of
supported VLANs: 1-3967, 4048-4093.
In order to verify that the configuration is correct from a vPC perspective, make sure to issue the following
command:
nexus7000# show vpc consistency-paramters global
vPC Role and Priority
Within the VDC, the following configurations are required.
First, the vPC needs to be enabled, as follows:
agg(config)# feature vpc
A domain needs to be defined as well as priorities to define primary and secondary roles in the vPC
configuration. The lower number has higher priority, so it wins.
Note: The role is nonpreemptive, so a device may be operationally primary but secondary from a configuration
perspective. Because spanning tree is preemptive, this may result in a mismatch between the spanning
tree root and the vPC operational primary device: