Abstract: End hosts share network performance and reliability information with their peers over a peer-to-peer network. The aggregated information from multiple end hosts is shared in the peer-to-peer network in order for each end host to process the aggregated information so as to profile network performance. A set of attributes defines hierarchies associated with end hosts and their network connectivity. Information on the network performance and failures experienced by end hosts is then aggregated along these hierarchies, to identify patterns (e.g., shared attributes) that are indicative of the source of the problem. In some cases, such sharing of information also enables end hosts to resolve problems by themselves.