Question
When SSO has been configured for SAML 2.0 and a user's federation identifier has been populated, how do they get redirected to the Identity Provider's login page?
Background
I'm working to configure a Salesforce instance to use a 3rd party Identity Provider. I've uploaded their certificate and filled out their settings in setup->security controls->single sign-on settings. I've also created a test user with a federation identifier.
I'm now trying to test that the user gets redirected to the 3rd party identity provider when trying to access salesforce, but I'm stuck. I've tried going to the standard login page and entering my current username and password and that just logs me without going to the identity provider. I've also tried going to the salesforce login url from my SSO settings (https://login.salesforce.com/?saml=XXXXXXXXXXX), but that just sends me to the same page. I'm sure I'm misunderstanding how this works, but I'd think both of the above would somehow see that the user has a federation identifier and then validate their session with the identity provider. What am I doing wrong here?
ps - I'm a total dunce when it comes to SSO and have been trying to educate myself with the plentiful resources on developerforce and the broader web, but I'm still pretty green.