▲ 7 How do you tell a real Googlebot from something pretending to be one? asked by vivida (David) 3 days ago A lot of traffic claiming to be Googlebot and I doubt most of it.
reverse dns then forward dns on the result
dig -x 66.249.66.1should give something under googlebot.com, and resolving that name should give the address back. fails either step, it is lyinguser agent is a string the client picks, worth nothing on its own