Hi, I am not sure if I fully understand your question..tcp-syn setting in the zone protection profile protects against TCP SYN attack. If however, someone is sending TCP non-SYN packets and if there is no corresponding existing TCP session, then such packets could "very likely" be malicious. You can choose to drop all such packets on the firewall through a different setting admin@PM-PA-2020# set deviceconfig setting session tcp-reject-non-syn Let me know if this doesn't answer your question, Thanks, Sandeep
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