You can auto-update the signature (from Cisco.com) if your AIP-SSM is running 6.1.x. You need a have a valid Cisco Services for IPS account for your IPS sensor. Older versions only allow auto-updating from a HTTP/FTP server running on your network (on to which someone has uploaded updates after manually downloading them from cisco.com).
Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community: