for todays password 25-4-12 use 665600, tomorrow 26-4-12 use 092224 (both codes will be useless after 12pm on each day)
as soon as you are into your system reset codes back to factory then reboot.
How did you get the passcodes? dahuasecurity support will not help me out. i have a c2-4416 also and i cannot get in. locked out 888888 and admin. no one knows the passwords.