Enabling a trusted realm permits users from your realm to send authentication requests to the trusted realm. When you add a trusted realm, the trusted realm is enabled by default. You can also enable your realm to authenticate users from the trusted realm. For instructions, see Enable Authentication Between Realms.
In the Security Console, click Administration > Trusted Realms > Manage Existing.
Use the search fields to find the trusted realm that you want to edit.
Select the trusted realm that you want to edit.
From the context menu, click Edit.
In the Trusted Realm Status field, select Enable Trusted Realm.