Hi,
The parameters for the log is like below:
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Therefore, if you want to use match condition with "string" parameter, you should use one of "string" parameters in the log (there are three string parameters in the log, %0%, %1% and %5%).
For example with your way, I think you can use %0% string (i.e. "MAC") as below:
configure log filter "DefaultFilter" add exclude events "nl.ClientAuthenticated" match string "MAC"Otherwise, you can also use other match condition, "mac-address", "ports" or "vlan" instead of "string" parameter.
Regards,