Please note that in order for Drupal to be accessible via the server's IP you should modify the .htaccess file in the folder where Drupal is installed. The line you should uncomment and modify is:
# RewriteBase /
If your Drupal is installed in the main public_html folder, you should change the above line to:
RewriteBase /~your_cPanel_username/
If your Drupal is installed in a subfolder, for example drupal/, you should change the above line to:
RewriteBase /~your_cPanel_username/drupal/