[Mediawiki-l] Making page private

[Roiki]

Hello there,
Could I make mediawiki private? That is:
* Could I set, only registered-user may read and edit the pages? And maybe, membership must be approved by webmaster or sysop.
* Could mediawiki be set so only local connection may connect to mediawiki, (i.e., http://127.0.0.1/mediawiki/index.php/Main_Page )
* or any other methods to make the page more secure and private.

Thank you...