When generate-basic-fec-only is enabled on a leaf node, LDP generates a basic opaque type 1 FEC.
When generate-basic-fec-only is enabled on the ABR, LDP accepts a lower FEC of basic opaque type 1 and generate a basic opaque type 1 upper FEC. LDP then stitches the lower and upper FECs together to create a cross connect.
When generate-basic-fec-only is enabled and the ABR receives a lower FEC of:
For recursive FEC with type 7 opaque, the ABR stitches the lower FEC to an upper FEC with basic opaque type 1.
For any FEC type other than a recursive FEC with type 7 opaque or a non-recursive FEC with type 1 basic opaque, ABR processes the packet in the same manner as when generate-basic-fec-only is disabled.