Router Cache Issues – Force Browser to Use Updated Web Files

The solution that I've used to solve this problem is to make sure the TTL on a page never has a chance to expire before it's refreshed - forcing an HTTP client running on one of my systems to get the slow load instead of an unlucky client request.

In my case, this involves wget on a cron, sending a special header to mark the requests and setting req.hash_always_miss based on this, forcing a new copy of the content to be fetched into the cache.

acl purge {
    "localhost";
}

sub vcl_recv {
    /* other config here */
    if (req.http.X-Varnish-Nuke == "1" && client.ip ~ purge) {
        set req.hash_always_miss = true;
    }
    /* ... */
}

For your content, this might mean setting the Varnish TTL to something like 5 minutes but having a cron'd wget configured to make a cache-refreshing request every minute.

0) As I can see you check https:// site but configuration for http:// version. I guess it's not a problem in your case but better to check that you edit right configuration file.
1) You should check what you got from upstream curl -I http://box1.example.com/page1 and I guess that there will be Set-Cookie header. So you should either add Set-Cookie to proxy_ignore_headers or remove cookies from upstream's reply. Or use separate locations: one for pages where you could ignore cookies for caching and another for pages where you can't ignore cookies.