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Ramakrishna Padmanabhan
Hello Joan, Our paper found that even "dynamic" addresses can stick around on home routers for months and sometimes even years. The duration for which a dynamic address persists on a home router is a function of the DHCP lease set by the ISP (Some DSL ISPs don't use DHCP and their addresses are typically assigned to customers' routers for much shorter durations). Anecdotal evidence (i.e., what I heard from ISPs) suggests that typical DHCP lease durations range from 24 hours to a month. However, addresses can remain assigned to home routers for much longer than the lease duration; this is because DHCP allows the home router to renew its lease before the lease expires. As long as the lease continues to be renewed, the home router's address will continue to persist.