Multiagent-based cooperative inter-AS diagnosis in ENCORE

If the Internet is to operate reliably, it is important to verify whether the routing information about an autonomous system (AS) is correctly spread throughout the Internet as the originating AS intends or not. Because the routing information changes as it spreads, it is necessary for the inter-AS diagnostic system to observe the routing information from outside the AS. Each AS is controlled by a single administrative authority based on that AS's own policy, so a cooperative distributed solution is desirable. To cope with these requirements, we have proposed a multi-agent-based inter-AS diagnostic system called ENCORE, where a collection of intelligent agents are located in multiple AS and perform collective observation and analysis. This paper describes its diagnostic functions. It focuses on the agents' autonomous observation actions and their ability to perform cooperative and efficient analysis of routing anomalies. We also discuss the effectiveness and limitations of ENCORE based on analysis of a real AS.