CFM CCM messages are not sent over LT interface hosted on MPC2E NG or MPC3E NG card.

When CFM is configured similar to:

oam {

 ethernet {

  connectivity-fault-management {

    maintenance-domain TEST-DOMAIN {

      level 2;

      maintenance-association TEST-ASSOCIATION {

        continuity-check {

          interval 10s;

        }

        mep 1 {

          interface lt-0/0/10.500;

          direction up;

          priority 3;

          auto-discovery;

        }

      }

    }

  }

 }

}

And LT interface is hosted on MPC2E NG or MPC3E NG card, system doesn't send CFM CCM message over this interface:

user@router> show oam ethernet connectivity-fault-management interfaces lt-0/0/10.500 extensive

Interface name: lt-0/0/10.500 , Interface status: Active, Link status: Up

 Maintenance domain name: TEST-DOMAIN, Format: string, Level: 2, MD Index: 1

  Maintenance association name: TEST-ASSOCIATION, Format: string, MA Index: 1

  Continuity-check status: enabled, Interval: 10s, Loss-threshold: 3 frames

  Interface status TLV: none, Port status TLV: none

  Connection Protection TLV: no

  Chassis ID: 38:4f:49:8b:10:aa

  Management Address: 10.219.23.31

  Sendid TLV: no

  MEP identifier: 1, Direction: up, MAC address: 3a:4f:49:8b:08:b8

  MEP status: running

  Defects:

   Remote MEP not receiving CCM         : no

   Erroneous CCM received            : no

   Cross-connect CCM received          : no

   RDI sent by some MEP             : no

   Some remote MEP's MAC in error state     : no

   Alarm Indication Signal state         : no

  Statistics:

   CCMs sent                   : 0 <<<<<< counter doesn't increase

   CCMs received out of sequence         : 0

  <snip>

The issue causes the CFM session to fail to establish on the peer router

This problem has been resolved in PR1788491. For more information on the releases that include the fix, please visit https://prsearch.juniper.net/Problemreport/PR1788491