Thank you. One learns something new everyday. And I feel humbled by most comments I read here. I did look up OpenBSD pf again, and it too does port knocking in

Thank you. One learns something new everyday. And I feel humbled by most comments I read here. I did look up OpenBSD pf again, and it too does port knocking in the kernel. My information was dated (left the misc mailing list at least 5 years ago).