What is the ruling on praying Fajr before the Subh prayer shortly after the Adhan?

"Al-Subh" and "Al-Fajr" are two names for one and the same entity, which is the obligatory Dawn Prayer (Fard Al-Subh). It is Sunnah (recommended practice) to pray two Rak'ahs before the obligatory prayer. If someone deviates and prays the obligatory prayer before the supererogatory (Nafl) prayer, their prayer is valid, even though they have deviated from the Sunnah. Praying the two Rak'ahs of the Sunnah prayer after the obligatory Dawn prayer is considered a make-up (Qada') and not a performance within its prescribed time (Ada') according to some scholars. It is more appropriate to make them up after the sun has risen, to avoid the difference of opinion of those who prohibit praying them after Fajr and before the sun has risen.