Want to use the API to login a user to ALL sites in a DNN instance.

eg: localhost & site2.localhost

so, I have a user and i want to authenticate it throw localhost AND site2.localhost AND all the portals.

currently i am authenticating only in localhost and it seems it doesnt login on site2.localhost...

I am using the API:

UserController.UserLogin(portal.PortalID, user, portal.PortalName, DotNetNuke.Services.Authentication.AuthenticationLoginBase.GetIPAddress(), true);

need help...