According to the Chhandogya Upanishad, the teacher of Sri Krishna was Ghora Angirasa. The Upanishad mentions Ghora Angirasa as one of the teachers who imparted knowledge to various students, including Krishna.

Chhandogya Upanishad:
The Chhandogya Upanishad is one of the ancient Upanishads, which forms a part of the Vedic scriptures. It is a philosophical text that explores deep spiritual and metaphysical concepts. The Upanishad contains a dialogue between Uddalaka Aruni, a sage, and his son Shvetaketu, where the father imparts knowledge to his son.

Ghora Angirasa:
Ghora Angirasa was a renowned sage and teacher mentioned in the Upanishads. He belonged to the Angirasa lineage and was known for his deep spiritual wisdom and knowledge. Ghora Angirasa is considered as one of the prominent teachers who shared their wisdom with various students, including Sri Krishna.

Imparting Knowledge to Sri Krishna:
According to the Chhandogya Upanishad, after completing his education at the Gurukul, young Krishna approached several teachers to gain further knowledge. One of those teachers was Ghora Angirasa. Krishna sought the guidance of Ghora Angirasa to deepen his understanding of spiritual and metaphysical concepts.

Importance of Teacher-Student Relationship:
In the ancient Indian education system, the relationship between a teacher and student held immense significance. Students would approach different teachers to gain knowledge in various subjects and fields. Each teacher was considered as a Guru, who would impart not just academic knowledge but also moral values and spiritual wisdom.

Conclusion:
According to the Chhandogya Upanishad, Ghora Angirasa was one of the teachers of Sri Krishna. As Krishna sought to expand his knowledge and wisdom, he approached Ghora Angirasa to receive guidance in spiritual and metaphysical concepts. The teacher-student relationship played a crucial role in ancient Indian education, where Gurus like Ghora Angirasa imparted their wisdom to shape the lives of their students.