After a career fair at my university, I applied and got an on campus interview. Overall it was behavioral, although my interviewer talked more than I did, I could barely get a word in edge-wise.

Very cordial and easy. Asked me to walk through my resume and asked if I had any questions about the program. Most of the interview was spent talking about Fannie Mae's business model. I didn't seem to mesh with the interviewer very well and knew walking out that I had not gotten a second interview, but regardless, it was a straightforward interview with no surprises.