How do you rate limit unidentified users? If you are treating all unidentified users, or at least all Google bots as 1 user and they consider each Google bot in

How do you rate limit unidentified users? If you are treating all unidentified users, or at least all Google bots as 1 user and they consider each Google bot instances with a unique ip and no credentials a unique user and are hitting a 429 with a single request they may be treating that as a 503 instead.