[SLE] Free software for detecting an intrusion?

Hello Can anyone suggest me a good and free software for detecting an intrusion on my server? I was thinking of something that can be configured to send a sound when the attempt of intrusion is made and give a report of all login and attempts of logins on my server. Thanks a lot. Regards Eduardo -- To unsubscribe send e-mail to suse-linux-e-unsubscribe@suse.com For additional commands send e-mail to suse-linux-e-help@suse.com Also check the FAQ at http://www.suse.com/support/faq