Authentication cookies cause error in non-authenticated site

We have a default site that requires authentication. This site has a sub-domain that does not require authentication. If a user is logged into the authenticated site (in Internet Explorer) and tries to access the public sub-domain, they get a "This page can’t be displayed" error. If they log out of the parent site, then they can access the sub-domain just fine. We know that Internet Explorer doesn't let go of Authentication cookie like the other browsers but we don't know why this is preventing the sub-domain from being accessible. What can we do to fix this?

Hi Joseph,

Thanks for the feedback but could you please give a little more details as it can't be reproduced locally? How do you protect the site to require authentication? It could be done by changing pages' permissions. Is this the case?
Is the same behavior in other browsers or this is valid only for IE? Are there any customizations on the login or you use the standard Sitefinity widgets?

Looking forward for your responses.

Thank you & Regards,
DimBo
Telerik

I know this is a super-late response, but we didn't have to deal with the issue for a while due to the subdomain being deactivated, so the issue kind of dropped. Plus, I hadn't noticed that I had gotten a response on the original post.

However, the subdomain has been reactivated and this is once again a problem.

So this is the situation. We have several sites set up in a multisite install, of which two are involved in this problem:

example.com
subdomain.example.com

example.com has the View pages section under Pages > Permissions for all pages set to Authenticated, with Denied Users set to Anonymous and No Access. There is a login page with the standard Sitefinity login widget on it which is used to authenticate users from an LDAP membership provider.

​subdomain.example.com has the View pages section under Pages > Permissions for all pages set to Anonymous, Authenticated, and Everyone. It, naturally, has no login page set.

In Internet Explorer (and Internet Explorer only), when a person is logged in to example.com, they cannot access subdomain.example.com at all. The server doesn't seem to respond to any request for subdomain.example.com the login for example.com is active. We get the "This page can’t be displayed" page in IE when trying to hit the site. Looking at the traffic in Fiddler, we simply get a HTTP/1.1 504 Fiddler - Receive Failure with the message "Fiddler] ReadResponse() failed: The server did not return a complete response for this request. Server returned 0 bytes." returned in the browser.

Hello Joseph,

We answered you in the support ticket opened.

Once you have the solution you can share it with the community.

Regards,
Svetoslav Manchev
Telerik