I don't think this is about Hyperic, it's more about how your network responds to network failures. The packets will take whatever path they're given through your routing tables etc. If each router can failover successfully and take over the routing and traffic of each other, Hyperic will keep working no matter what. Matter of fact, that's kind of how the internet is designed, each core router is supposed to re-route in case a router in their chain is overloaded or goes offline.