vifmgr.cluscheck.crcerrors alerts and ifstat receiving long frames due to MTU mismatch

Applies to

• ONTAP 9
• Network
  • Maximum Transmission Unit (MTU)

Issue

• ifstat shows that the port is receiving long frames

::>system node run -node Node1 -command ifstat e1d
-- interface  e1d  (5 days, 13 hours, 44 minutes, 30 seconds) --
RECEIVE
 Total frames:      438k | Frames/second:       1  | Total bytes:     32232k
 Bytes/second:       67  | Total errors:    32047  | Errors/minute:       4 
 Total discards:      0  | Discards/minute:     0  | Multi/broadcast:   561k
 Non-primary u/c:     0  | CRC errors:          0  | Runt frames:         0 
 Long frames:     32047  | Length errors:       0  | Alignment errors:    0 
 No buffer:           0  | Pause:               0  | Jumbo:               0 
 Noproto:             0  | Bus overruns:        0  | LRO segments:        0 
 ...

• One of the below events are repeatedly logged in EMS, depending on the ONTAP version
  • [Node1: vifmgr: vifmgr.cluscheck.crcerrors:alert]: Port e1d on node Node1 is reporting a high number of observed CRC errors.
  • [Node1: vifmgr: vifmgr.cluscheck.crcerrors:alert]: Port e1d on node Node1 is reporting a high number of observed hardware errors, possibly CRC errors.
  • [Node1: vifmgr: vifmgr.cluscheck.hwerrors:alert]: Port e1d on node Node1 is reporting a high number (at least 1 per 1000 packets) of observed hardware errors (CRC, length, alignment, dropped).
• The switch port is sending long frames

switch# show interface eth0/10
Ethernet0/10 is up
  RX
    0 jumbo packets  0 storm suppression bytes
  TX
    32047 jumbo packets