title: How can I ensure that IsInRole checks are not using cached credentials
body: <p>I have a WPF client that connects to a WCF service, and I want to lock down some of the functionality so that only certain users can perform certain actions. The WCF service impersonates the client user when executing service methods. The OS is Windows XP.</p>
  
  <p>I was reading <a href="https://stackoverflow.com/questions/5042847/check-isinrole-against-ad">this question</a> as part of my investigation into the best way to apply user roles to features in my application (I want to assign users to AD security groups, and then check IsInRole), and am worried that cached permissions will allow users who have had their permissions reduced to access functionality they no longer have permission to. Conversely, I am also worried that users who have had their permissions upgraded will need to log out of their windows account, or even that the WCF service might have to be restarted (worst case scenario) before they can access the new functionality.</p>
  
  <p>What is the simplest way to ensure that both client and server can immediately see changes to the AD security groups?</p>