Hello I am trying to use mod_radius on ubuntu. But i am getting error: Invalid command 'AddModule', perhaps misspelled or defined by a module not included in the server configuration. When i comment out the line with AddModule from httpd.conf i got the following error message. Invalid command 'AuthAuthoritative', perhaps misspelled or defined by a module not included in the server configuration. These are the enabled modules on apache alias.conf authn_file.load authz_host.load cgi.load mime.conf php5.conf ssl.conf alias.load auth_radius.load authz_user.load dir.conf mime.load php5.load ssl.load auth_basic.load authz_default.load autoindex.conf dir.load negotiation.conf setenvif.conf status.conf auth_mysql.load authz_groupfile.load autoindex.load env.load negotiation.load setenvif.load status.load And this is my apache version. Server version: Apache/2.2.8 (Ubuntu) Server built: Jun 25 2008 13:54:13