  Max Consensus-based Auction (MCA) protocols are an elegant approach to
establish conflict-free distributed allocations in a wide range of network
utility maximization problems. A set of agents independently bid on a set of
items, and exchange their bids with their first hop-neighbors for a distributed
(max-consensus) winner determination. The use of MCA protocols was proposed,
$e.g.$, to solve the task allocation problem for a fleet of unmanned aerial
vehicles, in smart grids, or in distributed virtual network management
applications. Misconfigured or malicious agents participating in a MCA, or an
incorrect instantiation of policies can lead to oscillations of the protocol,
causing, $e.g.$, Service Level Agreement (SLA) violations.
  In this paper, we propose a formal, machine-readable, Max-Consensus Auction
model, encoded in the Alloy lightweight modeling language. The model consists
of a network of agents applying the MCA mechanisms, instantiated with
potentially different policies, and a set of predicates to analyze its
convergence properties. We were able to verify that MCA is not resilient
against rebidding attacks, and that the protocol fails (to achieve a
conflict-free resource allocation) for some specific combinations of policies.
Our model can be used to verify, with a "push-button" analysis, the convergence
of the MCA mechanism to a conflict-free allocation of a wide range of policy
instantiations.
