AFAIU one major advantage of Clos/fat tree networks is that you'll do quite fine even with relatively dumb static routing protocols. Slim Fly, Dragonfly, and o

AFAIU one major advantage of Clos/fat tree networks is that you'll do quite fine even with relatively dumb static routing protocols. Slim Fly, Dragonfly, and other fancy network topologies tend to require adaptive non-minimal routing to handle adversarial traffic patterns, which Infiniband (or ethernet, for that matter) doesn't support.