Establishing Trust Between Domains
In previous versions of WebLogic Server (before 7.x), principals could be shared and trusted between domains by making the system passwords in those domains to be the same. Version 8.1 provides more security by adding a Credential attribute for each domain. In order for domains to trust each other, they must have the same Credential attribute. A simple string is used to set the attribute. To make this string more secure, use numbers and uppercase and lowercase letters.
To set the Credential attribute for a domain, click on the domain in the left panel of the administrator console. Click on the View Domain-wide Security Settings link in the right panel and then click on the Advanced node. Make sure that the Enable Generated Credential is unchecked, enter a string that represents the Credential attribute for this domain, and confirm it. Click the Apply button and reboot WebLogic Server. Perform these steps for each domain you want to have in a trust relationship.