One of the fundamental requirements of Cloud Computing is the capability to provide scalable, transparent and isolated networks. This is achieved by using L2 segmentation via 802.1Q VLANs or overlay approaches such as 802.1ad, VxLAN, ”Stateless Transport Tunneling” (STT) or ”Network Virtualization using Generic Routing Encapsulation” (NVGRE). All of these technologies struggle to provide the required level of scalability, flexibility, performance and network isolation within a Data Center. Research efforts in the area of classification have fundamentally approached these challenges by introducing identifiers for segmentation or providing overlay solutions to tunnel traffic. However, these research approaches are too specific without tackling the actual Cloud Computing classification challenges. Here, we investigate classification approaches with the goal of introducing a scalable, optional, hierarchical, end-to-end and transparent Layer 3 provider, service and tenant isolation scheme. This proposal addresses major challenges and limitations of current cloud classification schemes by offering these five advantages: (1) hierarchical endto-end classification, (2) transparency to upper-layer protocols, (3) optional for en-route and endpoint evaluation, (4) flexibility, and (5) improved performance over current overlay technologies. The solution proposal will be implemented and evaluated based on its feasibility, functionality, performance and usability in cloud-related use-cases.