Bathroom Sink Drain Connection

[astein29]

Hey all, first time posting. I have a question about a drain connection I have in my home. I am in the process of replacing a sink and drain and am having trouble installing my drain line. The fitting in the wall of my house is in the attached pictures. I replaced all of the drain line (including the plastic washers) and am experiencing a slip drip when testing the connection to the wall. I used the standard plastic tapered washers, but recently noticed that the fitting appears to be square cut (with not chamfer to allow the tapered washer to fit into). All of the new fittings have this chamfer, but the fitting in the wall appear to be different. My question is, what is the proper washer or gasket to use in this type of fitting? I bought a few rubber tapered washers, but haven't tried them yet. The old drain line had a plastic washer installed and didn't appear to be leaking. 1-1/4 drain line with a slip-type compression fitting.

Thanks for any help, and appologies if this question has already been asked.

Adam