A technique that facilitates application synchronization with a reservation protocol at a sender without application receiver participation in a computer network. According to the novel technique, the sender sends a path request message to a reservation receiver and may include a request for fast path failure notification to be returned to the sender. The reservation receiver (e.g., a reservation receiver proxy upstream from the application receiver) receives the path request, and in response, returns a reservation request message to the sender, including a request for fast reservation failure notification also to be sent to the sender (e.g., in response to detecting the fast path failure notification request, local policy/configuration, etc.). In the event that an intermediate node between the sender and reservation receiver detects an error during the path request or reservation request, the intermediate node sends corresponding fast failure notification to the sender. The sender may then synchronize, e.g., an application with the reservation protocol, based on receipt of a fast failure notification or a successful reservation request message.