FreeBSD has the sysctls you are looking for to control the reserved port range, allowing unprivileged users to bind (curious that Linux doesn't): $ sudo sy

FreeBSD has the sysctls you are looking for to control the reserved port range, allowing unprivileged users to bind (curious that Linux doesn't): $ sudo sysctl net.inet.ip.portrange.reservedlow=10 net.inet.ip.portrange.reservedlow: 0 -> 10 $ nc -vvl 1 ^C $ sudo sysctl net.inet.ip.portrange.reservedlow=0 net.inet.ip.portrange.reservedlow: 10 -> 0 $ nc -vvl 1 nc: Permission denied