ever since the initial tuning of the FreeBSD TCP/IP stack around version 4.x, I’ve found myself occasionally tinkering with the contents of /etc/sysctl.conf just to fine-tune things, you know
over time, numerous changes have been made to the FreeBSD TCP/IP stack, including the introduction of modularity. however, MacOS X, being based on FreeBSD, is more conservative and lacks certain options.
therefore, on my MacOS systems, I make use of the following
net.inet.tcp.mssdflt=1460 net.inet.tcp.minmss=536 net.inet.tcp.win_scale_factor=5 net.inet.tcp.randomize_ports=1 net.inet.tcp.blackhole=2 net.inet.tcp.icmp_may_rst=0 net.inet.udp.blackhole=1 net.inet.ip.redirect=0
there’s no magic involved here; these settings should help you utilize the full throughput of your internet link. generally speaking, those are very small changes and should be safe, but please always consult this with documentation and adjust to your specific deployment.
and enjoy enhanced performance :)