Link flapping as switch reports error: ACKS_RECV_FOR_LAST_10_PDUs: No Acks have been received on Interface Eth0/0/0 for last 60 DCBX PDUs

Issue

• Kernel logging shows link flapping and switch logging reports no DCBX PDU acks received:

  $ grep "[registered,removed] PHC" /var/log/messages
  Jun 22 13:32:18 localhost kernel: ixgbe 0000:84:00.0: removed PHC on p2p1
  Jun 22 13:32:19 localhost kernel: ixgbe 0000:84:00.0: registered PHC device on p2p1
  Jun 22 13:32:29 localhost kernel: ixgbe 0000:84:00.0: removed PHC on p2p1
  Jun 22 13:32:30 localhost kernel: ixgbe 0000:84:00.0: registered PHC device on p2p1
  Jun 22 13:32:30 localhost kernel: ixgbe 0000:84:00.0: removed PHC on p2p1
  Jun 22 13:32:30 localhost kernel: ixgbe 0000:84:00.0: registered PHC device on p2p1
  Jun 22 13:32:48 localhost kernel: ixgbe 0000:84:00.0: removed PHC on p2p1
  Jun 22 13:32:48 localhost kernel: ixgbe 0000:84:00.0: registered PHC device on p2p1
  Jun 22 13:33:00 localhost kernel: ixgbe 0000:84:00.0: removed PHC on p2p1
  Jun 22 13:33:00 localhost kernel: ixgbe 0000:84:00.0: registered PHC device on p2p1
  Jun 22 13:33:00 localhost kernel: ixgbe 0000:84:00.0: removed PHC on p2p1
  Jun 22 13:33:00 localhost kernel: ixgbe 0000:84:00.0: registered PHC device on p2p1
  

  2016 Jun 20 19:01:17.732 SWITCH %$ VDC-1 %$ %LLDP-FEX102-1-NO_DCBX_
  ACKS_RECV_FOR_LAST_10_PDUs: No Acks have been received on Interface Eth102/1/5 for last 10 DCBX PDUs
  2016 Jun 22 17:24:16.584 SWITCH %$ VDC-1 %$ %LLDP-FEX102-1-NO_DCBX_
  ACKS_RECV_FOR_LAST_10_PDUs: No Acks have been received on Interface Eth102/1/6 for last 10 DCBX PDUs
  2016 Jun 29 14:20:55.494 SWITCH %$ VDC-1 %$ %LLDP-FEX101-1-NO_DCBX_
  ACKS_RECV_FOR_LAST_10_PDUs: No Acks have been received on Interface Eth101/1/5 for last 10 DCBX PDUs
  2016 Jun 29 14:26:21.202 SWITCH %$ VDC-1 %$ %LLDP-FEX101-1-NO_DCBX_
  ACKS_RECV_FOR_LAST_10_PDUs: No Acks have been received on Interface Eth101/1/5 for last 20 DCBX PDUs
  2016 Jun 29 14:31:34.638 SWITCH %$ VDC-1 %$ %LLDP-FEX101-1-NO_DCBX_
  ACKS_RECV_FOR_LAST_10_PDUs: No Acks have been received on Interface Eth101/1/5 for last 30 DCBX PDUs
  2016 Jun 29 14:36:50.054 SWITCH %$ VDC-1 %$ %LLDP-FEX101-1-NO_DCBX_
  ACKS_RECV_FOR_LAST_10_PDUs: No Acks have been received on Interface Eth101/1/5 for last 40 DCBX PDUs
  2016 Jun 29 14:42:04.242 SWITCH %$ VDC-1 %$ %LLDP-FEX101-1-NO_DCBX_
  ACKS_RECV_FOR_LAST_10_PDUs: No Acks have been received on Interface Eth101/1/5 for last 50 DCBX PDUs
  2016 Jun 29 14:47:27.784 SWITCH %$ VDC-1 %$ %LLDP-FEX101-1-NO_DCBX_
  ACKS_RECV_FOR_LAST_10_PDUs: No Acks have been received on Interface Eth101/1/5 for last 60 DCBX PDUs
  2016 Jun 29 14:52:46.556 SWITCH %$ VDC-1 %$ %LLDP-FEX101-1-NO_DCBX_
  ACKS_RECV_FOR_LAST_10_PDUs: No Acks have been received on Interface Eth101/1/5 for last 70 DCBX PDUs
  2016 Jun 29 14:58:08.275 SWITCH %$ VDC-1 %$ %LLDP-FEX101-1-NO_DCBX_
  ACKS_RECV_FOR_LAST_10_PDUs: No Acks have been received on Interface Eth101/1/5 for last 80 DCBX PDUs
  2016 Jun 29 15:03:12.836 SWITCH %$ VDC-1 %$ %LLDP-FEX101-1-NO_DCBX_
  ACKS_RECV_FOR_LAST_10_PDUs: No Acks have been received on Interface Eth101/1/5 for last 90 DCBX PDUs
  2016 Jun 29 15:08:13.738 SWITCH %$ VDC-1 %$ %LLDP-FEX101-1-NO_DCBX_
  ACKS_RECV_FOR_LAST_10_PDUs: No Acks have been received on Interface Eth101/1/5 for last 100 DCBX PDUs