Configuring MPLS to Pop the Label on the Ultimate-Hop Router

You can control the label value advertised on the egress router of a label-switched path (LSP). The default advertised label is label 3 (Implicit Null Label). If label 3 is advertised, the penultimate-hop router removes the label and sends the packet to the egress router. By enabling ultimate-hop popping, label 0 (IPv4 Explicit Null Label) is advertised. Ultimate-hop popping ensures that any packets traversing an MPLS network include a label.

To configure MPLS to pop the label on the ultimate-hop router, include the explicit-null statement:

explicit-null;

You can configure this statement at the following hierarchy levels:

[edit protocols mpls]

[edit logical-systems logical-system-name protocols mpls]

Note: Juniper Networks routers queue packets based on the incoming label. Routers from other vendors might queue packets differently. Keep this in mind when working with networks containing routers from multiple vendors.

For more information about labels, see Label Description and Label Allocation.