I have two secure sites:

```
siteA.example.com
siteB.example.com

```

A common sign in page exists on siteA.example.com. If you visit siteB.example.com without logging in, you are redirected to siteA.example.com. The URL ends up looking like this:

<http://siteA.example.com/Account/LogOn?ReturnUrl=%2f>

This doesn't work for me, because the return URL actually just ends up taking you to the homepage of siteA.example.com even though the user visited siteB.example.com.

Is there a configurable way to fix this? Or should I just hook into one of the global life cycle events to change the response?