allow access to website only from certain ip addresses using htaccess file

Order deny,allow
Deny from all
Allow from 123.456.789.101
Allow from 234.567.890.123
Allow from 345.678.901.234

or (newer version of apache2)


  Require all denied
  Require ip 123.456.789.101
  Require ip 234.567.890.123
  Require ip 345.678.901.234