I wouldn't do this.   Hopefully, one of the stacks is near the MX250s.  Make that that stack the core switches.  Then, plug everything into the core switches. ... View more

Hi @PhilipDAth & @MerakiDave , Sorry to disturb but I have a quite similar scenario where I have 3 different stacks of MS225 switches as it can be seen below which I would like to connect directly to MX250 devices ( acting as ACTIVE-PASSIVE ). If I connect 2 ports of each stack ( one to the ACTIVE and another one to the PASSIVE MX device) will this work or should I take care of any loop (the RSTP will be enabled by default on global mode and port level as well but with its default settings). Here it is my scenario:    Thanks in advance, Regards ... View more