Ethernet over MPLS on vQFX10K2 not working

Hi, I am trying to get Ethernet over MPLS work on vQFX, here is the topology:

srv1---vqfx1----vqfx2--srv2

vqfx1 and vqfx2 are back to back connected on xe-0/0/0, srv1 and srv2 are connected to xe-0/0/1 on vqfx1 and vqfx2, respectivity as CE device, all VMs are running on virtualbox managed by vagrant, I verified both PE-CE connections are fine by temporarily creating an irb interface on vqfx. The goal of the setup is L2 connectivity between srv1 and srv2 over the layer 3 link between vqfx1 and vqfx2.

here is the configuration I have:

vagrant@vqfx-RE1# run show configuration interfaces xe-0/0/1
encapsulation ethernet-ccc;
unit 0 {
    family ccc;
}

{master:0}[edit]
vagrant@vqfx-RE1# run show configuration protocols l2circuit
neighbor 185.67.136.1 {
    interface xe-0/0/1.0 {
        virtual-circuit-id 100;
    }
}

### Both MPLS LSP and l2circuits are up

vagrant@vqfx-RE1# run show mpls lsp
Ingress LSP: 1 sessions
To              From            State Rt P     ActivePath       LSPname
185.67.136.1    185.67.136.254  Up     0 *                      RE1-to-RE2
Total 1 displayed, Up 1, Down 0

Egress LSP: 1 sessions
To              From            State   Rt Style Labelin Labelout LSPname
185.67.136.254  185.67.136.1    Up       0  1 FF       3        - RE2-to-RE1
Total 1 displayed, Up 1, Down 0

Transit LSP: 0 sessions
Total 0 displayed, Up 0, Down 0

{master:0}[edit]

vagrant@vqfx-RE1# run show l2circuit connections
Layer-2 Circuit Connections:<snip>
Legend for interface status
Up -- operational
Dn -- down
Neighbor: 185.67.136.1
    Interface                 Type  St     Time last up          # Up trans
    xe-0/0/1.0(vc 100)        rmt   Up     Jul 30 22:52:25 2018           1
      Remote PE: 185.67.136.1, Negotiated control-word: Yes (Null)
      Incoming label: 16, Outgoing label: 16
      Negotiated PW status TLV: No
      Local interface: xe-0/0/1.0, Status: Up, Encapsulation: ETHERNET
      Flow Label Transmit: No, Flow Label Receive: No

{master:0}[edit]

## ping between srv1 and srv2 does not work, interface statistics on xe-0/0/1 on either vqfx stays at 0

vagrant@vqfx-RE1# run show interfaces xe-0/0/1
Physical interface: xe-0/0/1, Enabled, Physical link is Up
  Interface index: 650, SNMP ifIndex: 517
  Link-level type: Ethernet-CCC, MTU: 1514, LAN-PHY mode, Speed: 10Gbps, Duplex: Full-Duplex,
  BPDU Error: None, Loop Detect PDU Error: None, Ethernet-Switching Error: None,
  Source filtering: Disabled
  Ethernet-Switching Error: None, MAC-REWRITE Error: None, Loopback: Disabled, Flow control: Disabled,
  Media type: Fiber
  Device flags   : Present Running
  Interface flags: SNMP-Traps Internal: 0x4000
  Link flags     : None
  CoS queues     : 8 supported, 8 maximum usable queues
  Current address: 02:05:86:71:ba:07, Hardware address: 02:05:86:71:ba:07
  Last flapped   : 2018-07-30 22:31:52 UTC (00:59:52 ago)
  Input rate     : 0 bps (0 pps)
  Output rate    : 0 bps (0 pps)
  Active alarms  : None
  Active defects : None
  PCS statistics                      Seconds
    Bit errors                             0
    Errored blocks                         0
  Ethernet FEC statistics              Errors
    FEC Corrected Errors                    0
    FEC Uncorrected Errors                  0
    FEC Corrected Errors Rate               0
    FEC Uncorrected Errors Rate             0
  Interface transmit statistics: Disabled

  Logical interface xe-0/0/1.0 (Index 568) (SNMP ifIndex 519)
    Flags: Up SNMP-Traps 0x4004000 Encapsulation: Ethernet-CCC
    Input packets : 0
    Output packets: 0
    Protocol ccc, MTU: 1514
      Flags: Is-Primary

What could be wrong?