Most of the instructions is outlined on FreeBSD wiki at: http://wiki.freebsd.org/SubversionPrimer/VendorImports nc(1) is very small and most of code are just copied as-is from OpenBSD. With a few exceptions: * --no-tcpopt: Local feature specific to FreeBSD. * -V: We use FIB to map what OpenBSD do for "rdomain" * -E, -e: These are mostly self contained IPsec extensions delphij@FreeBSD.org - Mar 23, 2010