ProxySG doesn't display an exception page when the requested URL is redirected

Products

• ProxySG Software - SGOS

Issue/Introduction

Why don't Notify User or exception/coaching pages work for URLs that are redirected?

Cause

The appliance can't return an exception page for a URL response that the browser doesn't display. If the requested URL triggers a redirect to another URL, the notification rule must match the new destination URL, not the original URL. For example, if the current condition is for the requested URL’s category, the category might not match that of the new redirected URL.

This issue can occur if policy includes the URL Shorteners category condition to guard against the Notify User VPM action. For example, requests for http://app.link result in a redirect and do not return an exception page, even though http://app.link matches the URL Shorteners category.

 

Resolution

Modify the exception policy to include a condition for the URL to which users are redirected.

For example, if users request the URL http://app.link, which redirects to https://branch.io/what-is-applink/, include a condition for https://branch.io/what-is-applink/. Refer to the following example:

define condition NotifyURLs
 url=branch.io/what-is-applink/
 <any_other_URLs_to_match>
end 

...
 
define condition _NotifyUser
 condition=__is_notifiable \
 condition=!__is_notify_internal \
 request.header.Cookie=!'notified-NotifyUser=1'
end
 
define string __NotifyUser_format
  <exception_page_definition>
end

...

<Proxy> 
  condition=NotifyURLs policy.NotifyUser