Is Single sign-on to the Enforce Server supported?
Customers would like to enable logging onto the Enforce server via Siteminder or Tivoli WebSeal. However, single sign-on for Symantec DLP is currently not supported.
Enhancement request PM-94 has been filed for the single sign-on feature, which includes integration into environments utilizing these products.
At this point there is no target release for this feature.
PM-1894 Support for SiteMinder for SharePoint 2010
PM-1895 Sharepoint Crawler returns site collections from default zone rather than custom zone
Here is more information on how SiteMinder works: