Sun OpenSSO Enterprise 8.0 Technical Overview

The Common Domain

The common domain is established for use only within the scope of identity provider discovery in a defined circle of trust. In OpenSSO Enterprise deployments, the identity provider discovery WAR is deployed in a web container installed in a predetermined and preconfigured common domain so that the common domain cookie is accessible to all providers in the circle of trust. For example, if an identity provider is available at, a service provider is available at, and the defined common domain is, the addresses will be and, respectively. If the HTTP server in the common domain is operated by the service provider, the service provider will redirect the user agent to the appropriate identity provider.