spanning-tree

Profile Config Commands

Enables spanning tree commands. Use these commands to configure the errdisable, multiple spanning tree and portfast settings.

Supported on the following devices:

Syntax

spanning-tree [errdisable|mst|portfast]
spanning-tree errdisable recovery [cause bpduguard|interval <10-1000000>]
spanning-tree mst [<0-15>|cisco-interoperability|enable|forward-time|hello-time|instance|max-age|max-hops|region|revision]
spanning-tree mst [<0-15> priority <0-61440>|cisco-interoperability [enable|disable]|enable|forward-time <4-30>|hello-time <1-10>|instance <1-15>| max-age <6-40>|max-hops <7-127>|region <LINE>|revision <0-255>]
spanning-tree portfast [bpdufilter|bpduguard] default

Parameters

spanning-tree errdisable recovery [cause bpduguard|interval <10-1000000>]
spanning-tree Configures spanning-tree related parameters
errdisable Disables or shuts down ports where traffic is looping, or ports with traffic in one direction
recovery Enables the timeout mechanism for a port to be recovered. This option is disabled by default.
cause bpduguard Specifies the reason for errdisable
  • bpduguard – Recovers from errdisable due to bpduguard
interval <10-1000000> Specifies the interval after which a port is enabled
  • <10-1000000> – Specify a value from 10 - 1000000 seconds. The default is 300 seconds.
 
spanning-tree mst [<0-15> priority <0-61440>|cisco-interoperability 
[enable|disable]|enable|forward-time <4-30>|hello-time <1-10>|instance <1-15>|
max-age <6-40>|max-hops <7-127>|region <LINE>|revision <0-255>]
spanning-tree Configures spanning-tree related parameters
mst Configures Multiple Spanning Tree (MST) commands

The MSTP provides an extension to STP to optimize the usefulness of VLANs. MSTP allows for a separate spanning tree for each VLAN group, and blocks all but one of the possible alternate paths within each spanning tree topology.
<0-15> priority <0-61440> Specifies the number of instances required to configure MST. Select a value from 0 -15.
  • priority – Sets the bridge priority to the specified value. This value is used to determine the root bridge. Use the no parameter with this command to restore the default bridge priority value.
    • <0-61440> – Sets the bridge priority in increments (Lower priority indicates greater likelihood of becoming root)
cisco interoperability [enable|disable] Enables CISCO interoperability

Enables interoperability with CISCO‘s version of MSTP, which is incompatible with standard MSTP. This setting is disabled by default.
enable Enables MST protocol
forward-time <4-30> Specifies the forwarding delay time in seconds
  • <4-30> – Specify a value from 4 - 30 seconds. The default is 15 seconds.
hello-time <1-10> Specifies the hello BDPU interval in seconds
  • <1-10> – Specify a value from 1 - 10 seconds. The default is 2 seconds.
instance <1-15> Defines the instance ID to which the VLAN is associated
  • <1-15> – Specify an instance ID from 1 - 10.
max-age <6-40> Defines the maximum time to listen for the root bridge
  • <6-40> – Specify a value from 4 - 60 seconds. The default is 20 seconds.
max-hops <7-127> Defines the maximum hops when BPDU is valid
  • <7-127> – Specify a value from 7 - 127. The default is 20.
region <LINE> Specifies the MST region
  • <LINE> – Specify the region name.
revision <0-255> Sets the MST bridge revision number. This enables the retrieval of configuration information.
  • <0-255> – Specify a value from 0 - 255. This default is 0.
 
spanning-tree portfast [bpdufilter|bpduguard] default
spanning-tree Configures spanning-tree related parameters
portfast [bpdufilter| bpduguard] default Enables PortFast on a bridge
  • bpdufilter default – Sets the BPDU filter for the port. The BPDU filter is disabled by default.

    The spanning tree protocol sends BPDUs from all ports. Enabling the BPDU filter ensures that PortFast enabled ports do not transmit or receive BPDUs.

  • bpduguard default – Guards PortFast ports against BPDU receive. The BPDU guard is disabled by default.

    Enabling the BPDU guard means this port will shutdown on receiving a BPDU.

    • default – Enables the BPDU filter and/or BPDU guard on PortFast enabled ports by default

Usage Guidelines

If a bridge does not hear BPDUs from the root bridge within the specified interval, assume the network has changed and recomputed the spanning-tree topology.

Generally, spanning tree configuration settings in the config mode define the configuration for bridge and bridge instances.

MSTP is based on instances. An instance is a group of VLANs with a common spanning tree. A single VLAN cannot be associated with multiple instances.

Wireless Controllers or service platforms with the same instance, VLAN mapping, revision number and region names define a unique region. Wireless Controllers or service platforms in the same region exchange BPDUs with instance record information within.

Example

nx9500-6C8809(config-profile-TestNX5500)#spanning-tree errdisable recovery cause bpduguard

nx9500-6C8809(config-profile-TestNX5500)#spanning-tree mst 2 priority 4096

nx9500-6C8809(config-profile-TestNX5500)#show context
profile nx5500 TestNX5500
 mint link ip 1.2.3.4
 mint level 1 area-id 88
 bridge vlan 1
  bridging-mode isolated-tunnel
  ip igmp snooping
  ip igmp snooping querier
 radius nas-identifier test
 radius nas-port-id 1
 neighbor-info-interval 6
 neighbor-inactivity-timeout 500
 spanning-tree mst 2 priority 4096
 spanning-tree errdisable recovery cause bpduguard
 autoinstall configuration
--More--
nx9500-6C8809(config-profile-TestNX5500)#

Related Commands

no Disables or reverts settings to their default
9037762-05 Rev AA