I can share the basics: User > Third-party owned Access > Aruba Core (with multiple MST instances) > LACP Trunk > Meraki Core  ... View more

LACP on two connections ... View more

Hi Tore, you'd think so but there is root bridge elections constantly, even with the other core set to a lower priority. ... View more

Hi Tore, unfortunately they run MSTP with multiple instance as they support multiple customers. Including ourselves. Managed to get the core config from the HP side though. stp instance 0 priority 4096 stp mode rstp stp bpdu-protection stp global enable   interface Bridge-Aggregation1 description to customer root switches port link-type trunk undo port trunk permit vlan 1 port trunk permit vlan xxxx link-aggregation mode dynamic stp root-protection ... View more

Tried this so far: Meraki and Aruba downstream are competing for root 1. Tried lowering cost for Core switches - no change 2. Raised the cost for Core switches - no change - Downstream switch priority - 4096   Powered core 1 switch off to rule out switch stack issues - no change   - Disabled RSTP on port 12 on Core-02 facing Aruba downstream - All traffic stopped flowing - Disabled RSTP globally - no change - Removed native vlan from port 12 - no change - RSTP is back enabled globally and on port 12   Pings are successful when Aruba downstream is root Once it changes to the Meraki device, pings drop It does this in 20 second intervals, repeats     ... View more

Yes, unfortunately don't have any choice as the third-party support other clients with same switches.  ... View more