share login between two different websites

Question

So I am having two different websites that use database sessions for login both have the same application name but for some reason I can't maintain login when I redirect from website A to website B

below are configuration for both website

<authentication mode="Forms">
      <!-- timeout should be 60 minutes (as per feedback from users).  The default value = 60 min -->
      <forms loginUrl="/secure/login" defaultUrl="~/Default.aspx" name="Name" enableCrossAppRedirects="false" protection="All" requireSSL="false" timeout="480" slidingExpiration="true" />
    </authentication> 


   <add name="AspNetSqlProfileProvider" connectionStringName="SqlServerConnectionString" applicationName="/" type="System.Web.Profile.SqlProfileProvider" />

I am guessing I need to some how create the authentication cookie under domain B but donno how without passing the login username and password ( Note, its not even an option)

Answer 1

On the authentication cookie configuration add domain=".domain.com"