[This is preliminary documentation and subject to change.]
The ROUTER_INTERFACE_TYPE type enumerates the different kinds of interfaces on a Windows NT router.
typedef enum _ROUTER_INTERFACE_TYPE {
    ROUTER_IF_TYPE_CLIENT,
    ROUTER_IF_TYPE_HOME_ROUTER,
    ROUTER_IF_TYPE_FULL_ROUTER,
    ROUTER_IF_TYPE_DEDICATED,
    ROUTER_IF_TYPE_INTERNAL,
    ROUTER_IF_TYPE_LOOPBACK
} ROUTER_INTERFACE_TYPE;
  Windows NT:  Use version 5.0 and later.
  Windows:  Unsupported.
  Windows CE:  Unsupported.
  Header: Declared in mprapi.h.