We develop StacKAT, a network verification language featuring loops, finite state variables, nondeterminism, and—most importantly—access to a stack with accompanying push and pop operations. By viewing the variables and stack as the (parsed) headers and (to-be-parsed) contents of a network packet, StacKAT can express a wide range of network behaviors including parsing, source routing, and telemetry. These behaviors are difficult or impossible to model using existing languages like NetKAT . We develop a decision procedure for StacKAT program equivalence, based on finite automata. This decision procedure provides the theoretical basis for verifying network-wide properties and is able to provide counterexamples for inequivalent programs. Finally, we provide an axiomatization of StacKAT equivalence and establish its completeness.

@article{paperbot3111,
  title = {StacKAT: Infinite State Network Verification},
  author = {Jules Jacobs and Nate Foster and Tobias Kappé and Dexter Kozen and Lily Saada and Alexandra Silva and Jana Wagemaker},
  journal = {Proceedings of the ACM on Programming Languages},
  volume = {9},
  number = {PLDI},
  year = {2025},
  doi = {10.1145/3729257}
}