No, they don't. As far as the agents are concerned, they are the master repository (so if an agent that is communicating with an AH tries to do an update from the master repo, in reality it will get the files from the AH.)
Thanks, thats all i needed to know.
Shame actually as i wanted to be able to use the DMZ Agent Handler (with an internet interface configured) as a fall back repository for all our clients (enterprise wide), and as i untick the Master Repository by default and mandate clients communicate with their local LAN repository, it would have worked nicely. Never mind, will have to just create a repository on the Agent Handler instead.