Thanks, everyone for your input. The consensus seems to be 2x unmanaged switch solution to avoid the awkward MS120 mgmt and remove the single point of failure.    @BogoMips You might be onto something here - I think my MS120-8 had a statically assigned IP from my ISP, which I then also gave to MX1 later on. Not sure how long the lease is for, but this could explain it.  ... View more