Network engineers like redundancy. It’s not that we just want double of everything – we want the networks we design and manage to be super fast, super smart, and super resilient. In the LAN and in the data center we’ve been logically joining network switches using technologies such as Cisco StackWise, the Virtual Switching System and Virtual Port Channels with fabric extenders in order to consolidate control and data plane activities and provide greater fault tolerance, easier management and multichassis etherchannel for path redundancy. These are great benefits, but they can be reaped only by proper design. Otherwise, an engineer may introduce more risk into the network rather than make it more resilient.