We do NOT return interfaces:
  - with obviously hacky and fake addresses: '000000xxxxxx'

  - when they are management (role == 'mngmnt') interfaces.
    Currently there is no OS visible HW for these, the corresponding
    MACs are just used by the management HW.

  - for Infiniband (guid != NULL) interfaces. We need support on
    the client side before we start sending those over.