A separate class of enterprise vulnerability scanners include subscription and turnkey products and services from companies such as Foundstone, nCircle, and Qualys. Products and services from these vendors provide vulnerability detection from dedicated platforms.

Qualys's QualysGuard application service provider (ASP) scans your network externally, as an attacker would. You can then visit the vendor's Web site to review the results and download scan or remediation reports. The vendor provides a simple method for rescanning for specific vulnerabilities and for tracking ongoing vulnerabilities as they're discovered. Services such as scheduled scans, automated report and ticket generation, and geographic-independent scanning together with aggregated results provide excellent scanning capabilities from one Web site.

The Foundstone and nCircle turnkey hardware scanners include sophisticated scanning and reporting features, such as trending and a daily score of your organization's vulnerability risk. These dedicated devices are tuned for vulnerability detection and remediation management and are entirely vendor supported. However, the extra capability comes at a steep price-much more than these products' software-based counterparts.