I downloaded the latest Domain Mapping version and installed domain-mapping.php and sunrise.php. I edited my wp-config.php by typing in: define( 'SUNRISE', 'on' );
Interesting these lines did not come in my wp-config.php as installed, so nothing to uncomment. I refresh after this edit.
I head over to Network Options: there is no space to input my IP address.
Using WP 3.01 multisite, working OK.
Why no place to input IP address?