When transmitting MPLS traffic towards a LAG, all traffic goes through a single port and does not Load balance / Distribute as expected.

This behaviour is seen for both IP and non-IP traffic, for when the incrementing field of the flows are the MPLS labels and/or the IP address.

Topology:

source ( spirent ) --> ( et-0/0/20:0 ) QFX5130 ( ae1.0 ) --> destination

• When packets ingress on et-0/0/20:0 without MPLS labels with just Ethernet + IP header + data payload having random source and destination IP addresses, they are distributed to multiple physical interfaces part of ae1.0 and forwarded out. 
• When packets ingress with MPLS Label value as 1 ( Router-Label ) or Randomised MPLS Label values with Ethernet + MPLS header + IP header + data payload having random source and destination IP addresses, load balancing does not happen and the packets are forwarded on the egress always using a single physical link on ae1.0.

We tried the following configuration but it did not help:

• set forwarding-options hash-key family mpls label-1
• set forwarding-options hash-key family mpls payload ip

QFX5130 uses TD4 ASIC, which does not support MPLS.