Role Manager in Web Farm?

Hello
I implemented single sign-on feature with same validationKey/decryptionKey configuration.
http://SingleLoginBox/Login.aspx
Once user logged-in by this Login.aspx, this user is able to access http://Web1 and http://Web2 without re-logging.
It works fine. However, I have a question about RoleManager.
In SingeLoginBox server, I use roleManager feature..
The configuration like this..
<roleManager enabled="true" defaultProvider="CustomRoleProvider">
            <providers>
                <clear/>
                    <add name="CustomRoleProvider" type="MyRolesProvider.MembersRoleProvider"  applicationName="/"
             />
...