def add_router_references(self, snet, address, dnets):
        """Add/update references to routers."""
        if _debug: NetworkServiceAccessPoint._debug("add_router_references %r %r %r", snet, address, dnets)

        # see if we have an adapter for the snet
        if snet not in self.adapters:
            raise RuntimeError("no adapter for network: %d" % (snet,))

        # pass this along to the cache
        self.router_info_cache.update_router_info(snet, address, dnets)
Add/update references to routers.