  An algorithm for $n-1$-strong-equillibrium for distributed consensus in a
ring with rational agents was proposed by Afek et al. (2014). A proof of
impossibility of $n-1$-strong-equillibrium for distributed consensus in every
topology with rational agents, when $n$ is even, is presented. Furthermore, we
show that the algorithm proposed by Afek et al. is the only algorithm which can
solve the problem when $n$ is odd. Finally, we prove that the proposed
algorithm provides a $n-2$-strong-equillibrium in a synchronous ring when $n$
is even.
