In interprovider VPN scenarios using BGP family inet labeled-unicast (RFC 3107), a PE router receives labeled IPv4 prefixes. For these routes to be considered valid and installed in the routing table, the BGP next-hop must be resolvable via a labeled path in the inet.3 routing table. If BGP cannot find a labeled path to the next-hop, the route is marked as hidden. The resolve-vpn parameter, configured under the [edit protocols bgp group family inet labeled-unicast] hierarchy, explicitly instructs the BGP process to perform next-hop resolution using the inet.3 table. This enables the router to find the required MPLS LSP or LDP path, resolves the next-hop, and makes the route active.

A. The explicit-null parameter is used to control penultimate-hop-popping (PHP) behavior, typically for QoS purposes, and does not influence BGP next-hop resolution.

B. Enabling traffic-engineering under OSPF allows the IGP to flood information for RSVP-TE, but it does not directly configure BGP's route resolution mechanism.

D. The traffic-engineering parameter under the protocols mpls hierarchy is a container for RSVP-TE configuration; it is a prerequisite for building LSPs but does not fix the BGP resolution logic itself.

1. Juniper Networks TechLibrary

BGP Feature Guide

resolve-vpn: "To resolve routes received with the BGP labeled-unicast address family

you must configure the resolve-vpn statement. This statement enables the router to resolve the next hop in the inet.3 routing table." This document directly states the function of the resolve-vpn parameter in solving the exact problem described.

Source: Juniper Networks

BGP Feature Guide

resolve-vpn topic.

2. Juniper Networks TechLibrary

MPLS Applications User Guide

"Understanding BGP Labeled Unicast for Inter-AS VPNs": "For the routes to be resolved

the PE router must have a labeled path to the BGP next hop... To enable the PE router to resolve labeled BGP routes

you must configure the resolve-vpn statement for the BGP labeled unicast address family." This guide explains the necessity of this command specifically within the context of Inter-AS (interprovider) VPNs.

Source: Juniper Networks

MPLS Applications User Guide

section on BGP Labeled Unicast for Inter-AS VPNs.

3. Juniper Networks TechLibrary

Routing Protocols Configuration Guide

"Configuring BGP Labeled Unicasts": This section details the configuration of the inet-labeled-unicast address family and notes that for proper operation

especially in VPN contexts

next-hop resolution must be correctly configured

pointing to the use of resolve-vpn to utilize the inet.3 table.

Source: Juniper Networks

Routing Protocols Configuration Guide

section on BGP Labeled Unicasts.