Alcatel-Lucent 7450 Manual page 580

LDP Shortcut for IGP Routes
When an IPv4 packet is received on an ingress network interfacea subscriber IES interface, or a
regular IES interface, the lookup of the packet by the ingress forwarding engine will result in the
packet being sent labeled with the label stack corresponding to the NHLFE of the LDP LSP when
the preferred RTM entry corresponds to an LDP shortcut.
If the preferred RTM entry corresponds to an IP next-hop, the IPv4 packet is forwarded unlabeled.
Page 580 7450 ESS MPLS Guide