Layer 3 Routed Access - The use of a Layer 3 routed access network for the fabric provides the highest level of availability without the need to use loop avoidance protocols such as Spanning- Tree (STP), interface bundling techniques using link aggregation technologies such as EtherChannel, and Layer 2 redundancy technologies like StackWise Virtual (SVL), Virtual Switching System (VSS), or Nexus Virtual Port-Channels (vPCs).