Traffic drop will be observed when Label MPLS traffic egressing out on the IRB interface as IPv4

Label MPLS (labeled-unicast) traffic egressing out on the IRB interface as IPV4 will result in packet drops. This issue happens when an MPLS route points to aggregate next-hop with MPLS->IPV4 over IRB, the ingress forwarding state of aggregate next-hop with MPLS->IPV4 over IRB is not correctly programmed and pointing to discard. This issue might be observed in the scenario having IRB configured under default routing-instance and destination prefix is learned by IRB through BGP route advertisement through/over Egress-L2-Lag (AE interface) or directly reachable via IRB (not learned through BGP route advertisement) over Egress-L2-Lag. Example Topology: Source-Host x.x.x.x ----> [ Ingress-Provider-Edge] <--- L3-VPN ---> ae<x> [Egress-Provider-Edge-Device | QFX| IRB (Default RI) ] ae<x> ------> Apstra <----- Destination-Host X.X.X.X

On QFX10K platforms, Label MPLS (Multiprotocol Label Switching) (labeled-unicast) traffic egressing out on IRB (Integrated routing and bridging) interface as IPV4 traffic can get dropped.

Trigger:

This issue might be seen if the following conditions are met:
* On QFX10K platforms
* Label MPLS (labeled-unicast) traffic egressing out on the IRB interface as IPV4
* IRB is configured under default routing-instance
* Destination prefix is learned by IRB through BGP route advertisement through/over Egress-L2-Lag (AE interface) or directly reachable via IRB (not learned through BGP route advertisement) over Egress-L2-Lag.

Workaround:
Have egress interface physical L3 interface instead of IRB or move to VRF routing-instance.