Is there a way to protect against attacks?
Sadly you cannot stop an attacker from sending deauthentication packets.
But to minimize damage make sure you use WPA2 with a long good password. An attacker will usually send deauthentication packets so he can capture a handshake and brute force it to gain the WiFi password. By having a hard to crack password you are making the attack much harder and longer and in some cases almost impossible.
Is there a way to know attacker ?
As said in the comments, the attacker is probably close by so walk around a little and find him.
You can read a little more about the subject in this answer.