I forgot to add one thing. In the same discussion, lest there should be any doubt, Narayana is again mentioned by his other name, Aniruddha - तद्वै विप्राः प्रवदन्तेऽनिरुद्धम् | in Mbh 12.339.18. (Learned Brahmanas call Him by the name of Aniruddha.)