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Do Brocade switches(FastIron, NetIron, ICX, etc) support using a per vlan spanning tree or do they only support a single spanning tree instance for all VLANs?

If they support per vlan:

  • Is it enabled by default?
  • What command(s) are used to disable/enable per vlan spanning tree for STP and RSTP?

We are not going to use MST so disregard that as a semi-answer.

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  • Classic STP and RSTP are VLAN agnostic. There's no way to run separated spanning trees depending on VLANs - that's what MSTP is for.
    – Zac67
    Nov 24, 2022 at 8:24

2 Answers 2

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It's important to note that PVST/PVST+ is Cisco proprietary.

They do support one instance of STP per VLAN, and it is enabled by default. You can enable/disable STP on the following levels (taken from the NetIron config docs):

  • Globally - Affects all VLANs
  • Individual VLAN - Affects all ports within the specified VLAN. When you enable or disable STP within a VLAN, the setting overrides the global setting. Thus, you can enable STP for the ports within a VLAN even when STP is globally disabled, or disable the ports within a port-based VLAN when STP is globally enabled.
  • Individual Port - Affects only the individual port. However, if you change the STP state of the primary port in a LAG group, the change affects all ports in the LAG group.

Depending on your code rev, you can enter config mode for the VLAN and either do:

[no] spanning-tree

or

[no] rstp
[no] spanning-tree 802-1w (used on older versions of code)

I know that newer NetIron gear has PVST/PVST+ compatibility modes which you can turn on at the interface level with:

pvst-mode

But this also implies that you're going to be running MST, which you said you're not going to do.

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According to the documentation I have here (specifically pertaining to the ICX series), enabling PVST should be as simple as configuring spanning-tree within each VLAN.

It is not enabled by default. Commands for configuring PVST are rather self explanatory:

(config-vlan-10)#spanning-tree rstp

Enables RSTP for VLAN 10

Other pertinent tab-complete commands are available under the spanning-tree command

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