  We show how a scalable preconditioner for the primal discontinuous
Petrov-Galerkin (DPG) method can be developed using existing algebraic
multigrid (AMG) preconditioning techniques. The stability of the DPG method
gives a norm equivalence which allows us to exploit existing AMG algorithms and
software. We show how these algebraic preconditioners can be applied directly
to a Schur complement system of interface unknowns arising from the DPG method.
To the best of our knowledge, this is the first massively scalable algebraic
preconditioner for DPG problems.
