A distributed, highly available service discovery & internal load balancer for distributed systems (microservices and containers). You can use the layer 4 load balancer by specifying a VIP from the Marathon UI. The VIP must be specified in the format IP:port, for example: 10.1.2.3:5000. Alternatively, if you're using something other than Marathon, you can create a label on the port protocol buffer while launching a task on Mesos. This label's key must be in the format VIP_$IDX, where $IDX is replaced by a number, starting from 0. Once you create a task, or a set of tasks with a VIP, they will automatically become available to all nodes in the cluster, including the masters.