deny root login from console

[Selvi]

Due to some problem i need to restrict root login from all ipaddress including console login except 3 machines.    Is there any way to allow root login from only 3 machines. Normal users can login as usual including console login   I know this is risk but i can manage .Because some peoples knows root passwd. i can't say them do not login as root. istead of this i have decided as above   Thanks in advance selvi