Each VLAN must be specifically LDP-enabled in order to set up LDP adjacencies over the interface. Before LDP can be enabled on a VLAN, the VLAN must be configured to support MPLS as described in Adding MPLS Support to VLANs.
This command enables LDP on one or all VLANs for which MPLS has been configured.
Note
If you have enabled LDP and MPLS on an IGP interface that is used to reach a particular destination, make sure that you enable LDP and MPLS on all additional IGP interfaces that can reach that same destination (for example, enable LDP and MPLS on all OSPF VLANs that are connected to the backbone network).