Operation to resolve an interface specification

An "resolve-interface" operation on the root resource of a host or server to validate an interface criteria.

Params would be the same as what is passed to interface=X:add.

Return value would be the String representation of the InetAddress that would be chosen if an equivalently configured interface were added and started.

Purpose it to allow clients (e.g. the admin console) to validate interface specs before adding/updating them.

The same operation should be added on the interface itself. Perhaps there if no params are provided the existing config in the model is validated?