One thing that does worry me, the Meraki's are running RSTP and the Catlyst C9300 (which are the core for some of the sites) are running MSTP (This was confirmed by Meraki Support).  Therefore even though my VLAN is only used on the P2P link, will it still be calculated in the STP algorithm?   I did hear that RSTP (and potentially) RPVST are coming out soon for the Catalysts (I am managing these via the Meraki dashboard).     Thanks   ... View more

Hi Elwin   The P2P vlan is exclusively used for the P2P link - I will try this on my next set up which should be in a month or two.   Thanks for the advice.   ... View more

Hi Elwin,   Thank you for the response.  I would like all of my P2P links to be L3, therefore should I set RSTP to disabled on the ports at each end of the P2P link?  I am always hesitant of disabling STP!   Thanks   ... View more

Hi, I have the same conundrum.  I have a college with multiple campuses.  Each campus has a core stack (some are Meraki and some are C9300 all managed via Meraki).  Each core has been set as the root bridge with a priority of 4096.  Each campus has multiple edge stacks and Wifi AP's (all Meraki).  The P2P links between all campuses are set to Access and use a SVI to mimic a L3 connection.  OSPF is run to share routes.  I too see some of the P2P links set to a discarding state to avoid a loop.  I cannot find anything definitive on Meraki website on how to configure a port that will be used as a P2P link (L3 only).  All of P2P ports have the RSTP Enabled and STP Guard Disabled.  I am always weary of disabling RSTP on a port.  But from what I have read from this thread, it is ok to do so?  All P2P links are on the core stacks.   Thanks     ... View more