Application Request Routing (ARR) is a module included with Microsoft Internet Information Server (IIS) that provides rule-based routing, client and host name affinity, load balancing of HTTP server requests, and distributed disk caching. Many administrators have adopted ARR as a way to provide Reverse Proxy for publishing back-end applications over the Internet now that Microsoft Forefront Threat Management Gateway (TMG) has been discontinued. Most of the other functionality that was present in TMG is not replicated in ARR. KEMP Loadmaster load balancers coupled with Dell SonicWall firewalls can replace the missing functionality.