Internet Protocol (IP) address assignment information is collected from Address Allocation Tables (AATs) of a plurality of IP address assigning registrars. The information is processed and stored into one or more data structures. The information is accessed to determine a proximity measure for any two given IP addresses. In one embodiment, the proximity determination includes the determination of superblock memberships of the IP addresses, comparison of the assigning registrars, as well as the location countries of the IP addresses. In one embodiment, the proximity detection is applied to locating IP addresses of peer providers of a resource. In one embodiment, Autonomous System (AS) numbers and IP addresses for a plurality of peer providers for a plurality of resources are also collected and organized into one or more data structures; this organized information of the peer providers is also used in locating the closest peer providers of a resource in terms of network topology.