clicking the back button in django admin site
What's happening
Chrome is not fetching the page again, just displaying what was there "before" and Chrome stored in its cache.
Chrome is not even asking your webserver about the page, and as far as your app knows, you never went back to that page.
Don't worry about it
However, if you:

Refresh the page
Try to POST some data,

Chrome will have to hit your webserver, and Django will redirect to the login page.
I am new to Django . I am trying out the django admin/auth system. I logged into the admin site first and then I logged out . After logging out and clicking the back button on my browser(Chrome) I am still getting the old admin page . Should it not be redirected to login page instead? If so Is there some configuration issue on my setup?