CE-----,xe-0/0/40:1>---QFX10k2--<ae24>-------<ae2>--QFX5100-48s-<xe-0/0/0>---CE

The is L2 vpn/ PW between QFX10k and QFX5k


Below is the output from 10k. As you can see- PW is up

root@m07-51# run show l2circuit connections 
Neighbor: 165.237.193.30 
    Interface                 Type  St     Time last up          # Up trans
    xe-0/0/40:1.0(vc 1)       rmt   Up     Nov  8 13:41:47 2023           1
      Remote PE: 165.237.193.30, Negotiated control-word: Yes (Null)
      Incoming label: 16, Outgoing label: 16
      Negotiated PW status TLV: No
      Local interface: xe-0/0/40:1.0, Status: Up, Encapsulation: ETHERNET
      Flow Label Transmit: No, Flow Label Receive: No
*****************************************************************
When I initiate MPLS pings from 5k towards 10k, pings work -

root@mrhgmort-ios22g1-5100-1> ping mpls l2circuit interface xe-0/0/0
!!!!!
--- lsping statistics ---
5 packets transmitted, 5 packets received, 0% packet loss

****************************************************************

Pings from 10k to 5k don't work

root@m07-51# run ping mpls l2circuit interface xe-0/0/40:1 

Warning: License key missing; requires 'l2circuit' license

...
--- lsping statistics ---
5 packets transmitted, 0 packets received, 100% packet loss
******************************************************************************************************

Tshoot performed

We did pcap on10k and 5k and realized that 10K does send out MPLS ECHO to 5k, but 5k doesn't respond

File name - 'qfx10kbidi' Check packets 3 112,131,150,171 and 190 in the attached pcap in the attachments section.

The issue is specific to QFX5100 due to BRCM bug which is fixed in 21.4R3-S6 ands7. This wont be fixed in later releases for this platform as 5100 is EOS