Outlook Web Access : Client Cache with APM

Problem this snippet solves:

The iApp / Deployment guide suggest to disable App Cache for OWA when using F5 APM.

This irule provide a solution to prevent "Access policy evaluation is already in progress" page and keep cache App cache enabled.

How to use this snippet:

enable this irule on the exchange virtual server.

Code :

when ACCESS_SESSION_STARTED {
    set landinguri [ACCESS::session data get session.server.landinguri]
    switch -glob $landinguri {
        "/owa/plt1.ashx?*" -
        "/owa/sessiondata.ashx?appcacheclient=1" -
        "/owa/userspecificresourceinjector.ashx?*&appcacheclient=1*" -
        "/owa/manifests/appCacheManifestHandler.ashx?owamanifest=1" {
            ACCESS::respond 403 -version "1.1" noserver "Connection" "Close"
            ACCESS::session remove
            return
        }
    }
}