This signature fires when a configurable threshold for all ICMP traffic is crossed. The level of all ICMP traffic is monitored for any sudden increases to detect possible denial-of-service attack conditions.This signature is disabled by default. In order to properly utilize this signature, it must be put into "diagnostic" mode. This is done by enabling the signature, setting the "Rate" parameter to zero, and letting the sensor operate for a period of time. While in "diagnostic" mode, alarms will be generated with the current rate of all ICMP traffic. Using these rates, a threshold should be chosen to indicate when the level of all ICMP traffic is no longer within the acceptable range for the network being monitored. After the threshold is determined, it should be used as the value of "Rate" parameter for this signature.Note: This signature should not be left in "diagnostic" mode for permanent operation due to the performance overhead created by monitoring traffic rates.
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