REP Implementation - Ring within a Ring

[jmyers1973]

I am pretty sure I know the answer to this, but I am looking for a bit of guidance.  I have an industrial plant with many switches, they are currently using STP for their loop prevention protocol and we are recommending that they implement REP for faster convergence and less impact.  The question I have is that there are basically two rings on the plant.  One is inside the other ring but it is connected to the same switches and same ports as the primary ring would be on the lower ring.  

I have been racking my brain trying to figure out a way to make this work but it looks like I just may have to create a primary ring from the 9300's to the plant IE-3300's (I know I will have to move the connections on the IE's to the top switch in the loop) and then use Port Channels and STP from the connected IE's to the top layer 3650's and the uplink.  

Has anyone run into anything like this in the past and made it work with REP?  I would appreciate any help on this.

[Enes Simnica]

gDay @jmyers1973 also great question G! So Rep won’t work with two rings that overlap on the same switches and ports. It needs one clean loop. Ur plan is the right approach: build a single Rep ring between the 9300s and IE-3300s, and use port-channels with STP toward the 3650s. That’s the only stable way I’ve seen it work....

hope it helps and GOOD LUCK!

-Enes