You can use the Data ONTAP ping throttling mechanism and its ip.ping_throttle.drop_level option to help avoid denial-of-service attacks that can occur when using ICMP.
If your storage system supports a very large number of CIFS clients that use ICMP pings to determine CIFS shares accessibility, you can increase the ping throttling threshold value in the ip.ping_throttle.drop_level option.
If a large number of CIFS clients are experiencing temporary or persistent unavailability of the storage system, you should check to see if the ping throttling threshold has been exceeded for the storage system. If so, you can increase the ping throttling threshold value.