It isn't too hard to set up. Basically install the Agent Handler on the server you want to be an agent handler, configure EPO and it's pretty much done.
Agent handler install is in the EPO install, under "Agent Handler" directory. You will need the SQL authentication credentials, as well as knowledge of your EPO server.
Under "Configuration", "Agent Handlers", you need to create "Agent handler Assignment" rules, and set the agent priority.
You may also want to create Agent handler groups depending on your environment.
In addition to what Mal has said, I strongly recommend you read the Agent Handler White Paper (which is on the knowledge base.) There are a number of common misconceptions about agent handlers and there's a pretty good chance you don't actually need one
Thanks Mal & Joe........
AH (Agent Handler) is used for load balancing or external policy enforcement and package deployment. If you put AH in DMZ.
When you put AH in dmz make sure to trust between LAN > DMZ and DMZ > WAN. Read AH white paper for ports.
When you are installing the AH on the server, make sure that if you use NT auth on the database the server must be in the domain, if not use the SQL usr\pwd
in menu > configuration > agent handlers. Remember to enable the inactive AH and edit Published DNS Name and Published IP address so the agents can reach it from the outside.