WASHINGTON — James. B. Comey, the former F.B.I. director, was met with raised fists and chants of “no justice, no peace” by protesters on Friday as he delivered the keynote address at Howard University’s convocation, marking a rocky re-emergence into public life since he was fired by President Trump in May.

Mr. Comey gamely delivered his speech, at a ceremony marking the school’s 150th opening convocation, amid disruptions from more than a dozen protesters in the packed, large auditorium who interrupted him repeatedly to let him know he was not welcome on campus. He has accepted a yearlong post as an endowed chair at Howard.

Ignoring the disruptions, Mr. Comey encouraged the crowd to “listen with an attitude that they might actually be convinced of something. Instead, what happens in most of the real world and about four rows in this auditorium, is that people don’t listen at all.”