When using the test tool, I can authenticate one user, but no others. The user that was able to authenticate is a domain admin account. I tried another domain admin account and it didn't work.
I've tried setting Base DN to ou=xx,dc=yy,dc=zz.
I've tried setting Base DN to just dc=yy, dc=zz.
I've tried leaving Base DN blank.
I get the same results, even with Base DN blank. That single user can authenticate but no others can. I tried adding the suffix @ourdomain.foo, but that broke the one user that could authenticate.