nanog mailing list archives
Re: Multiple Spanning Tree Instance 0
From: Chris Marget <chris () marget com>
Date: Fri, 27 Feb 2015 06:03:24 -0500
On Wed, Feb 25, 2015 at 4:09 PM, Graham Johnston <johnstong () westmancom com> wrote:
We are planning a migration from Rapid PVST+ to Multiple Spanning Tree to better support a mixed vendor environment. My question today is about MST Instance 0. In practice do you map any VLANs there other than VLAN 1?
I'd hoped to see some responses to this thread because I recently had some awkward moments with a vendor after discovering that their switch wouldn't allow me to map VLANs to STP instances in an arbitrary manner. I took the position that the implementation was faulty, their position was more along the lines of "Well, why would you want to do that anyway?" Addressing the question directly, I know of two switching platforms which force the operator to map VLANs other than 1 into instance 0. Some Broadcom FASTPATH based platforms fail to mention VLAN 4094 in any 'show spanning-tree' commands, but always maps it to instance 0. The implementation of MST available on Cumulus Linux only supports instance 0, maps all VLANs there. My Cumulus experience is a bit dated, this may have changed in the last year. /chris
Current thread:
- Multiple Spanning Tree Instance 0 Graham Johnston (Feb 25)
- Re: Multiple Spanning Tree Instance 0 Chris Marget (Feb 27)