VL2: AScalableandFlexibleDataCenterNetwork

To be agile and cost eective, data centersshould allow dynamic re- source allocation across large server pools. In particular, the data center network should enable any server to be assigned to any ser- vice. Tomeetthesegoals, wepresentVL2,apracticalnetworkarchi- tecture that scales to support huge data centers with uniform high capacity between servers, performance isolation between services, andEthernetlayer-2semantics. VL2uses(1)�ataddressingtoallow service instances to be placed anywhere in the network, (2) Valiant Load Balancing to spread trac uniformly across network pat hs, and (3) end-system based address resolution to scale to large server pools,withoutintroducingcomplexitytothenetworkcontrolplane. VL2's design is driven by detailed measurements of trac and fault data from a large operational cloud service provider. VL2's imple- mentationleveragesprovennetwork technologies, already available atlowcostinhigh-speedhardwareimplementations,tobuildascal- able and reliable network architecture. As a result, VL2 networks can be deployed today, and we have built a working prototype. We evaluate the merits of the VL2 design using measurement,analysis, and experiments. Our VL2 prototype shues 2.7 TB of data amon g 75 serversin 395 seconds - sustaining a ratethat is 94% of the max- imum possible.