I have implemented several virtual networks using VRF-lite across 6500s, 4500s, 3750s, 3560s, 3550s, and now ME 3400Gs. All of these platforms support IP multicasting within VRFs except the 4500 Sup V and Sup IV. The Sup 6-E supports it. This seems like a very arbitrary decision. Does anyone understand the rationale for this?