There was a related story of ECMP load balancing a while back. There were good comments on some of this benefits & challenges, https://news.ycombinator.com/item

There was a related story of ECMP load balancing a while back. There were good comments on some of this benefits & challenges, https://news.ycombinator.com/item?id=7811412 https://news.ycombinator.com/item?id=7811412. To your first point use an external node, outside te data path, as your control plane. To the second the simplest is to mange layer 3 ecmp on top of mobile layer 2 address assignments. Think bgp to carp'd next hops. Depending on your router implementation you also have more choices than simple 5 tuple for the ecmp hash inputs.