Master MDM not listening on 6611

Hi all.

I have a peculiar situation that's frustrating me to no end. I have a ScaleIO 2.0 cluster that's essentially been doing fine for quite a while now with just a few exceptions that I'm not worried about here. The components run as VMs on ESXi 6.5 hosts. The configuration was three nodes (3 ESXi hosts each with their own VM, with the ESXi hosts configured as SDCs). I'm in the process of expanding this and using this as an opportunity to upgrade to 2.6. The 2.6 install went fine and as an experiment I too the 2.0 cluster and expanded it from 3 nodes to 5 nodes. That went fine too - except I forgot to reconfigure the SDCs and lost access to the MDM cluster when it went to the new manager node. So, I went in, reconfigured one of the ESXi scini modules, powered down the VMs, rebooted the ESXi host, and when everything came up the manager seemed to be unable to listen on 6611.

I'm simplifying what I've done here - partly because I've done a bunch of changes and testing at this point I can't remember every step. But the long and short of it is, that I now have an MDM cluster that speaks fine on 9011, but won't listen on 6611. I can reboot the VM (and the ESXi host), watch the MDM cluster switch ownership to another manager, but when I do a netstat -an it doesn't show it listening on 6611. I can do a scli --query_cluster and see the cluster is a master on the host in question. I haven't changed network configurations on the VMs or the ESXi hosts. (Those I did change for tests I've changed back.) I also had a copy of one of the VM's which I spun up and that didn't help either.

I've tried looking in the logs in /opt/emc/scaleio/mdm/logs, and don't see anything blatantly visible - but there's a lot in there and I admit I could have missed something. What more can I look at to find out why this is behaving like this? It just boggles the mind that the mdm processes are listening fine on one network port, but not on another. Another option that I'm looking for - is there a way to blow away the MDM installations and rebuild from scratch (while saving the data on the SDSes)?

Thanks.