Odd issue with HP and Cisco

[Brian_Fulbrook]

I have a campus network. Building A is made up of HP 3800 Switches.  Building B is made up of Cisco Meraki Switches.

The Hp and Meraki switches are running RSTP for spanning tree and the apporiate vlans have been trunked on the Meraki side and tagged on the HP side. Randomly one of the switches in the stack will go offline and drop all connectivity for 5 to 10 minutes and then come back online. I have worked with both Hp and Meraki on this and can't pin point any issues. Any advised would be greatful.

[Vince-Whirlwind]

Do they need to use spanning tree between buildings? Presumably not, cross-campus connections should be stable?

You could stop sending BPDUs on the interfaces that connect the two buildings. See what happens.