When you install multiple instances of Access Manager on different host servers, the additional instances are not added to the platform server list or the realm/DNS aliases. You must explicitly add the values for the additional Access Manager instances, as follows:
Log in to the Access Manager 7 2005Q4 Console as amadmin on the first Access Manager host server.
In the Access Manager Console, click Configuration, System Properties, and then Platform.
Add each additional Access Manager instance to the Platform Server List under Instance Name:
Add the Realm/DNS alias for each additional Access Manager instance:
In the Access Manager Console, click Access Control and then the root (top-level) realm under Realm Name.
Under Realm Attributes, add the Access Manager instance to Realm/DNS Aliases and then click Add. For example: amserver2.example.com
After you have added all instances, click Save.