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Spanning Tree instance missing Nexus 9k? not enabled by default as per documentation

jason.gomes
Level 1
Level 1

Hi, a bit confused here. Documentation suggest PVST+ enabled by default, and on every VLAN on creation.

But we don't have any spanning tree topology, and "show spanning-tree summary" says its enable

Rapid PVST+

Rapid PVST+ is the default spanning tree mode for the software and is enabled by default on the default VLAN and all newly created VLANs.

A single instance, or topology, of RSTP runs on each configured VLAN, and each Rapid PVST+ instance on a VLAN has a single root device. You can enable and disable STP on a per-VLAN basis when you are running Rapid PVST+.

 

From <http://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus9000/sw/6-x/layer2/configuration/guide/b_Cisco_Nexus_9000_Series_NX-OS_Layer_2_Switching_Configuration_Guide/b_Cisco_Nexus_9000_Series_NX-OS_Layer_2_Switching_Configuration_Guide_chapter_0...>

CLI Output:

new-svrswi01# show spanning-tree summary
Switch is in rapid-pvst mode
Port Type Default                        is disable
Edge Port [PortFast] BPDU Guard Default  is enabled
Edge Port [PortFast] BPDU Filter Default is disabled
Bridge Assurance                         is enabled
Loopguard Default                        is enabled
Pathcost method used                     is short
vPC peer-switch                          is enabled (non-operational)
STP-Lite                                 is disabled

new-svrswi01# show run | inc spann
spanning-tree port type edge bpduguard default
spanning-tree loopguard default
spanning-tree vlan 51-54 priority 4096
  spanning-tree link-type point-to-point
  spanning-tree link-type point-to-point
  spanning-tree port type network
  spanning-tree guard none
  spanning-tree port type network
  spanning-tree port type network

new-svrswi017# show spanning-tree brief
No spanning tree instance exists.
new-svrswi01# show spanning-tree detail
No spanning tree instance exists.
new-svrswi01# show spanning-tree root
new-svrswi017#
new-svrswi017# show spanning-tree
No spanning tree instance exists.

Does anyone know if there is something we need to turn under the VLAN configuration?? 

.. config..

vlan 1-2,51-54,998-999
vlan 2
  name MGMT
vlan 51
  name SRV-Data_1
vlan 52
  name SRV-Data_2

2 Replies 2

Reza Sharifi
Hall of Fame
Hall of Fame

Hi,

By default RSTP is enabled per vlan. You don't need any other command unless you have multiple switches and you want to prefer one switch as root and the other one as backup root. 

Switch is in rapid-pvst mode

HTH

Paul Chapman
Level 4
Level 4

Hi Jason -

Is this is a new switch?  Are any of the ports in switchport mode (not routed or FabricPath) and in a "connected" state?  You don't get any topology until you have L2 ports (access or trunk) online.  You also don't get any topology if all the ports are FabricPath ports (i.e. a FP spine switch).

PSC

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