When the Prophet (ﷺ) finished the 'Isha prayer, he would perform eleven Rak'ah before the Fajr prayer, concluding each two Rak'ah with Taslim (i.e., saying As-Salamu 'Alaikum) and observing the Witr (odd) at the end. When the Mu'adhdhin finished proclaiming Adhan for the Fajr prayer and it was dawn, he would rise and perform two short Rak'ah, and then would lie down on his right side till the Mu'adhdhin came to (inform) him about Iqamah.

[Muslim].