Spanning Tree

Spanning Tree Protocol (STP) configuration prevents Layer 2 loops and provides redundant path management on NX-OS devices, supporting PVST+ (per-VLAN spanning tree) and MST (Multiple Spanning Tree) modes with bridge assurance and loop guard for enhanced network stability. Global settings control STP mode selection, pathcost method, FCoE integration, linecard ISSU behavior, L2 gateway STP domain ID, and default edge port behavior. Per-VLAN settings allow customization of timers, priority, and root bridge designation. Spanning tree interface-level configuration manages BPDU filter, BPDU guard, port cost, guard mode (root/loop), link type, port type (edge/network/normal), port priority, and MST interoperability settings across Ethernet and port-channel interfaces.

Diagram

Classes

configuration (nxos.devices)

Name	Type	Constraint	Mandatory	Default Value
spanning_tree	Class	`[spanning_tree]`	No

ethernets (nxos.devices.configuration.interfaces)

Name	Type	Constraint	Mandatory	Default Value
spanning_tree	Class	`[spanning_tree]`	No

port_channels (nxos.devices.configuration.interfaces)

Name	Type	Constraint	Mandatory	Default Value
spanning_tree	Class	`[spanning_tree]`	No

spanning_tree (nxos.devices.configuration)

Name	Type	Constraint	Mandatory
bridge_assurance	Boolean	`true`, `false`	No
fcoe	Boolean	`true`, `false`	No
l2_gateway_stp_domain_id	Integer	min: `0`, max: `200000000`	No
linecard_issu	Choice	`disruptive`, `non-disruptive`, `auto`	No
loopguard	Boolean	`true`, `false`	No
mode	Choice	`mst`, `pvrst`	No
pathcost_method	Choice	`auto`, `short`, `long`	No
port_type_edge_default	Boolean	`true`, `false`	No
port_type_edge_bpdufilter_default	Boolean	`true`, `false`	No
port_type_edge_bpduguard_default	Boolean	`true`, `false`	No
vlans	List	`[vlans]`	No

spanning_tree (nxos.devices.configuration.interfaces.ethernets)

Name	Type	Constraint	Mandatory
bpdufilter	Boolean	`true`, `false`	No
bpduguard	Boolean	`true`, `false`	No
cost	Integer	min: `0`, max: `200000000`	No
guard	Choice	`root`, `loop`, `none`	No
link_type	Choice	`auto`, `p2p`, `shared`	No
port_type	Choice	`edge`, `network`, `normal`	No
port_priority	Integer	min: `0`, max: `224`	No
mst_pre_standard	Boolean	`true`, `false`	No
mst_simulate_pvst	Boolean	`true`, `false`	No

vlans (nxos.devices.configuration.spanning_tree)

Name	Type	Constraint	Mandatory
vlan_id	Integer	min: `1`, max: `4094`	Yes
forward_time	Integer	min: `4`, max: `30`	No
hello_time	Integer	min: `1`, max: `10`	No
max_age	Integer	min: `6`, max: `40`	No
priority	Integer	min: `0`, max: `61440`	No
root	Choice	`primary`, `secondary`	No
diameter	Integer	min: `2`, max: `7`	No

Examples

Example 1: PVST+ mode with bridge assurance, loopguard, and default edge port settings

nxos:
  devices:
    - name: LEAF1
      configuration:
        spanning_tree:
          mode: pvrst
          loopguard: true
          bridge_assurance: true
          port_type_edge_default: true
          port_type_edge_bpduguard_default: true

Example 2: MST mode with long pathcost on a spine switch

nxos:
  devices:
    - name: SPINE1
      configuration:
        spanning_tree:
          mode: mst
          bridge_assurance: true
          loopguard: true
          pathcost_method: long

Example 3: Spanning tree with FCoE support, linecard ISSU behavior, and L2 gateway domain ID

nxos:
  devices:
    - name: BORDER-LEAF1
      configuration:
        spanning_tree:
          mode: pvrst
          bridge_assurance: true
          loopguard: true
          fcoe: true
          linecard_issu: non-disruptive
          l2_gateway_stp_domain_id: 100

Example 4: Per-VLAN spanning tree with root bridge designation and custom timers

nxos:
  devices:
    - name: LEAF1
      configuration:
        spanning_tree:
          mode: pvrst
          vlans:
            - vlan_id: 100
              priority: 4096
              root: primary
              diameter: 3
              forward_time: 15
              hello_time: 2
              max_age: 20
            - vlan_id: 200
              priority: 8192
              root: secondary

Example 5: Interface-level spanning tree with edge port, BPDU guard, and MST interop settings

nxos:
  devices:
    - name: LEAF1
      configuration:
        interfaces:
          ethernets:
            - id: 1/1
              spanning_tree:
                port_type: edge
                bpduguard: true
                guard: root
                mst_pre_standard: true
                mst_simulate_pvst: true
          port_channels:
            - id: 100
              spanning_tree:
                port_type: network
                guard: loop
                link_type: p2p
                cost: 500
                port_priority: 128

Spanning Tree Protocol (STP) configuration prevents Layer 2 loops and provides redundant path management on NX-OS devices, supporting PVST+ (per-VLAN spanning tree) and MST (Multiple Spanning Tree) modes with bridge assurance and loop guard for enhanced network stability. Global settings control STP mode selection, pathcost method, FCoE integration, linecard ISSU behavior, and L2 gateway STP domain ID. Spanning tree interface-level configuration manages BPDU filter, BPDU guard, port cost, guard mode (root/loop), link type, port type (edge/network/normal), and port priority across Ethernet and port-channel interfaces.