I'm changing the following settings in the Terminal, and after I reboot, they return to their default values.
sysctl net.inet.tcp.always_keepalive=1
sysctl net.inet.tcp.keepidle=20000
sysctl net.inet.tcp.keepinit=20000
sysctl net.inet.tcp.keepintvl=20000
Any idea how to make these settings permanent?