A label switch router (LSR) in a label-switched path (LSP) may receive, from an ingress edge LSR, a Multi-Protocol Label Switching (MPLS) echo request, where the LSP includes a tunnel having details that are hidden by a Nil Forward Equivalency Class (FEC). The LSR may determine whether the LSR is an egress node for the tunnel in the LSP based at least in part on one or more labels in the MPLS echo request. The LSR may, in response to determining that the LSR is the egress node for the tunnel in the LSP, send an MPLS echo reply that indicates the LSR as being the egress node for the tunnel in the LSP.