Source Address Validation: A Survey of Mechanisms, Measurement, and Deployment

Source address validation checks whether a packet is entitled to use its claimed Internet Protocol source address at a particular network boundary. Although filtering recommendations have existed since the 1990s, research continues to address incomplete deployment, asymmetric routing, changing address assignments, and limited visibility into enforcement. This survey reviews literature and standards from 1996 through October 2026. We organize mechanisms by the evidence they use: local address bindings, routing information, explicit source announcements, packet authentication, and observed traffic behavior. We distinguish host, prefix, and autonomous system guarantees, and separate packet source validation from route origin validation. We then compare cooperative probing, remote inference, and passive observation, emphasizing the difference between observing successful spoofing and establishing the presence of a filter. An evaluation framework connects false acceptance, false rejection, convergence, implementation cost, and protection under partial deployment. The synthesis identifies three recurring obstacles: the mismatch between forwarding information and source authorization, the mismatch between a measurement sample and a deployment claim, and the mismatch between deployment cost and protection received. We conclude with research directions in authorization semantics, safe rule updates, reproducible evaluation, and verifiable deployment. All reported numerical findings remain attributed to their original studies; this survey contributes no new Internet measurement experiment.