Mash

The archie [1] system is a replicated, centralized directory server for all Anonymous FTP sites in the Internet. This centralized approach has not scaled well. The march [2] system provides an alternate solution, using IP Multicast to distribute directory queries directly to FTP hosts. march suffers from highly redundant broadcast messages during expanding-disc search. We propose a solution to the problem of multicast flooding during expanding-disc searches by utilizing an automatically-configured hierarchy of query servers. This system, dubbed MASH , confines the multicast flooding primarily to those nodes at the frontier of each new search radius. We provide a mechanism and protocol for building a self-organizing, two-level hierarchy of MASH servers. We also provide an experimental implementation built on march [5].