On Wed, Feb 25, 2015 at 4:09 PM, Graham Johnston <[email protected]> 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
