CLUSTER NETWORK DEGARDED : Frequent Link Flapping due to faulty Cisco switch port

Applies to

Issue

• From the event logs, ONTAP reports Cluster Network Degraded due to "link flapping"

Mon Apr 11 10:47:50 -0700 [Node-15: vifmgr: vifmgr.port.monitor.failed:error]: The "link_flapping" health check for port e0a (node Node-15) has failed. The port is operating in a degraded state.
Mon Apr 11 10:47:50 -0700 [Node-15: vifmgr: callhome.clus.net.degraded:alert]: Call home for CLUSTER NETWORK DEGRADED: Frequent Link Flapping - Cluster port e0a on node Node-15 has experienced multiple link down notifications.

• SFP was replaced on Port e0a from Storage end, still receiving alerts:

slot 0: Dual 40/100G Ethernet T62100-MEZZ
        e0a MAC Address:    d0:39:ea:a6:56:53 (auto-100g_sr4-fd-up)
            QSFP Vendor:         AVAGO          
            QSFP Part Number:    AFBR-89CDHZ     
            QSFP Serial Number:  AF2249S000Z    

• From "show tech-support" output collected from the CISCO Switch, port error (output discards) are being reported with multiple flaps reported at switch end:

2024 Apr 11 06:37:28 switch-sw-01 %ETHPORT-5-IF_DOWN_LINK_FAILURE: Interface Ethernet1/9 is down (Link failure)
2024 Apr 11 06:37:31 switch-sw-01 %ETHPORT-5-SPEED: Interface Ethernet1/9, operational speed changed to 100 Gbps
2024 Apr 11 06:37:31 switch-sw-01 %ETHPORT-5-IF_DUPLEX: Interface Ethernet1/9, operational duplex mode changed to Full
2024 Apr 11 06:37:31 switch-sw-01 %ETHPORT-5-IF_RX_FLOW_CONTROL: Interface Ethernet1/9, operational Receive Flow Control state changed to off
2024 Apr 11 06:37:31 switch-sw-01 %ETHPORT-5-IF_TX_FLOW_CONTROL: Interface Ethernet1/9, operational Transmit Flow Control state changed to off
2024 Apr 11 06:37:31 switch-sw-01 %ETHPORT-5-IF_UP: Interface Ethernet1/9 is up in mode trunk

Ethernet1/9 is up
admin state is up, Dedicated Interface
  Hardware: 1000/10000/25000/40000/50000/100000 Ethernet, address: 5c3e.0663.c5ac (bia 5c3e.0663.c5ac)
  MTU 9216 bytes, BW 100000000 Kbit , DLY 10 usec
  reliability 255/255, txload 12/255, rxload 2/255
  Encapsulation ARPA, medium is broadcast
  Port mode is trunk
  full-duplex, 100 Gb/s, media type is 100G
RX
    426701180513 unicast packets  1449865 multicast packets  1073438 broadcast packets
    258654702302309 input packets  770744434704032677 bytes
    199085499394 jumbo packets  0 storm suppression bytes
    0 runts  2 giants  0 CRC  0 no buffer
    2 input error  0 short frame  0 overrun   0 underrun  0 ignored
    0 watchdog  0 bad etype drop  0 bad proto drop  0 if down drop
    0 input with dribble  0 input discard
    0 Rx pause
  TX
    578287829194 unicast packets  63927280 multicast packets  24117240 broadcast packets
    237316577234214 output packets  1293229669503717771 bytes
    404291883556 jumbo packets
    0 output error  0 collision  0 deferred  0 late collision
    0 lost carrier  0 no carrier  0 babble  94115 output discard            
    0 Tx pause