$ mkdir /Library/StartupItems/Firewall
$ vi /Library/StartupItems/StartupParameters.plist

{
  Description     = "Customized Firewall Rules";
  Provides        = ("Firewall");
  Requires        = ("NetworkExtensions");
  OrderPreference = "None";
  Messages =
  {
    start = "Starting Customized Firewall Rules.....";
    stop  = "Stopping Customized Firewall Rules.....";
  };
}

$ vi /Library/StartupItems/Firewall/Firewall

#!/bin/sh

. /etc/rc.common

IPFW=/sbin/ipfw
StartService ()
{
    ConsoleMessage "Setting Customized Firewall Rules"
    ConsoleMessage "    Prevent from receiving anything from other office at udp port 2222."
    ${IPFW} add deny udp from any to any 2222 via en*
    ConsoleMessage "    Prevent Microsoft Office's piracy detection mechanism from broadcasting product IDs and access information through a random tcp port greater than 3000 (the ones we saw were all in the range 3000 to 3999) to local subnet."
    ${IPFW} add deny tcp from any to any 3000-3999 in recv en* setup
    ConsoleMessage -S
}

StopService ()
{
    ConsoleMessage "Flushing Customized Firewall Rules"
    ${IPFW} -f flush
}

RestartService ()
{
    ConsoleMessage "Using New Customized Firewall Rules"
    StopService
    StartService
}

RunService "$1"

$ chmod +x /Library/StartupItems/Firewall/Firewall

$ sudo /sbin/SystemStarter start "Firewall"

$ sudo /sbin/SystemStarter stop "Firewall"

$ /Library/StartupItems/Firewall/Firewall start
$ /Library/StartupItems/Firewall/Firewall stop
$ /Library/StartupItems/Firewall/Firewall restart