Redirect instance-url/login.do to some URL before logging in

[SnehalKarke]

Disallow login.do page to restrict users from backdoor entry. Whenever a user try to use /login.do it should redirect to sso login url.

[abhimanyu3]

These posts might help:

Enable external authentication

https://www.servicenowguru.com/integration/single-sign-on/removing-modifying-default-servicenowcom-l...

[NIkesh1]

\

Have you found a solution for this, even I have almost the same requirement :

[James Bengel]

I don't know if this is strictly on point for your use case or not, but I had a similar requirement a couple of weeks ago.  In our case, we needed external user redirected to the service portal login, and internal users directed to the UI.  I created a role for internal users, assigned it to the groups that needed UI access, then made a small change in the Script include SPEntryPage

Within the getFirstURL function, I added:

	getFirstPageURL: function() {
		
		var session = gs.getSession();
		this.logProperties('before', session);
		var check = session.getRoles();

		// has roles and is not a Service Portal page - go to UI16
		var nt = session.getProperty("nav_to");
		var isServicePortalURL = new GlideSPScriptable().isServicePortalURL(nt);
		var redirectURL = session.getProperty("login_redirect");

		if (session.hasRole('ncccs_internal') && !redirectURL && !isServicePortalURL){
			return;
			} else {
				    if(!session.hasRole('itil')){
				    session.clearProperty("starting_page");		
				    session.putProperty("starting_page", this.portal);		
				    session.clearProperty("login_redirect");		
				    session.putProperty("login_redirect", this.portal);		
            }
        }

That did the job for us, and no matter how much you tinker with the address bar, access to UI is disallowed unless you have the ncccs_internal role.