This section provides important information to describe the different configuration options used to populate the required BGP AD and generate the LDP generalized pseudowire-ID FEC fields. There are a large number of configuration options that are available with the this feature. Not all these configurations option are required to start using BGP AD. A very simple configuration automatically generates the required values used by BGP and LDP. In most cases, deployments provide full mesh connectivity between all nodes across a VPLS instance. However, capabilities are available to influence the topology and build hierarchies or hub and spoke models.