Meraki will be the STP root for only (maximum) vlan 1?

[MicJameson]

Hello Meraki tech gods.

I have suspect information that " This Meraki device (MS225-24P-HW) will be the STP root for only (maximum) vlan 1."

Questions: 

1. Does Meraki device (MS225-24P-HW) run RSTP?

2. Is Meraki device MS225-24P-HW able to be the STP (and PVSTP) (and RSTP) root for more than vlan 1?

Thank you!

[MarcP]

Yes, it can run RSTP:
Switch -> Switch settings

Will be the root for all vlans configured on it.

[MicJameson]

Thank you for your reply.

Can Meraki device MS225-24P-HW be the RSTP root for many vlans at the same time?

[MarcP · Accepted solution]

As written, it will be the root bridge in your network, means also for all known vlans on the switch. 🙂

Have a look into @Brash post bbelow as well:

Meraki switches run RSTP.

https://documentation.meraki.com/MS/Port_and_VLAN_Configuration/Configuring_Spanning_Tree_on_Meraki_...

They are interoperable with (but do not run) MST and PVST. The Vlan 1 requirement is if you connect a Meraki switch to a device that does PVST. The connecting device must have a PVST instance on vlan 1 in order for the Meraki switch to receive BPDU's.

https://documentation.meraki.com/MS/Deployment_Guides/Advanced_MS_Setup_Guide#PVST.2FPVST.2B

---

[Brash]

Meraki switches run RSTP.

https://documentation.meraki.com/MS/Port_and_VLAN_Configuration/Configuring_Spanning_Tree_on_Meraki_...

They are interoperable with (but do not run) MST and PVST. The Vlan 1 requirement is if you connect a Meraki switch to a device that does PVST. The connecting device must have a PVST instance on vlan 1 in order for the Meraki switch to receive BPDU's.

https://documentation.meraki.com/MS/Deployment_Guides/Advanced_MS_Setup_Guide#PVST.2FPVST.2B

[GIdenJoe]

Meraki switches will not send BPDU's on the MAC address that PVST and RPVST use so if you are running in a mixed environment you will have a bit of a disconnect in some cases.

If you have a Catalyst switch as root for everything then you should be fine.
If you have the MS as root for RSTP then a Catalyst switch will be root for all the other VLAN's.
Your best course of action if you have to make your MS switch root for everything is run MST on the Catalyst switches and make sure that you are not root for any instance.  Best even limit your MST configuration to a single instance (IST).

[kev2five]

Hi, 
I'm planning to retain a Catayst Core running rpvst and keeping it as root. 
As long as I allow vlan 1 over the trunks to the MS switches will I have compatibility whilst retaining my current Catayst rpvst config?
I got this from Meraki support:
"If using PVST, this must only be running in VLAN 1 and the MSs should not be the root" 

From reference support documentation this seems clearer, in that I don't have to strip out other vlans from the rpvst configuration on catayst core:
This is a Cisco proprietary protocol on Catalyst/Nexus switches that is compatible with spanning tree (802.1D) and RSTP (802.1w). It is important to note however that as Rapid-PVST is a multi-VLAN spanning tree protocol, MS series switches can participate in spanning tree only when a spanning tree instance is running on VLAN 1 of all switches. In addition, VLAN 1 must be allowed on all trunk ports running Rapid-PVST, so that BPDUs are seen by the Meraki switches in the topology.  In this configuration, the MS series switches should never be the STP Root Bridge.

[kev2five]

Tested today, with and without vlan1. Without vlan 1 Meraki thought it was root. With vlan 1 Meraki was happy to say the catalyst core was root. 

[meraki-newbie]

did you just allow vlan 1 as native? or just allow vlan 1 on the vlan list with another native vlan?