Acabei de encontrar uma página de suporte da Microsoft explicando algo chamado Recurso de Métrica Automática.
A metric is a value that is assigned to an IP route for a particular network interface that identifies the cost that is associated with using that route. For example, the metric can be valued in terms of link speed, hop count, or time delay. Automatic Metric is a new feature in Windows that automatically configures the metric for the local routes that are based on link speed. The Automatic Metric feature is enabled by default, and it can also be manually configured to assign a specific metric.
Para mais informações e tabelas com valores, consulte a página de suporte do msdn aqui .