  We consider light-cone quantized ${\rm{QCD}}_{1+1}$ on a `cylinder' with
periodic boundary conditions on the gluon fields. This is the framework of
discretized light-cone quantization. We review the argument that the light-cone
gauge $A^+=0$ is not attainable. The zero mode is a dynamical and gauge
invariant field. The attainable gauge has a Gribov ambiguity. We exactly solve
the problem of pure glue theory coupled to some zero mode external sources. We
verify the identity of the front and the more familiar instant form approaches.
We obtain a discrete spectrum of vacuum states and their wavefunctions.
