Mongodb tools mongotop and mongostat do not support authentication. But they advertise support it in the --help message.
Triple verified my admin username/password is correct but was unable to connect.
An strace confirmed there where no authentication attempt.
After a look at tools/
{stat,top}.cpp I realized authentication advertisement is inherited from base class but auth() is not called anywhere in doRun().
Since I am not a C++ guy I cannot create a good enough pull request so I opened this issue.
Feel free to correct me if any of my assumptions are incorrect!