configurar paquetes red mac

Donde se configura en mac OS X para que acepte todos los paquetes que detecte, en linux se hace:

$ echo 1 > /proc/sys/net/ipv4/ip_forward

o

$ cat /proc/sys/net/ipv4/ip_forward

donde diablos esta eso en mac os x????

Lo que leí por ahí es que:
Hacer esto en Mac OS X:
sysctl -w net.inet.ip.fw.enable=1
sysctl -w net.inet.ip.forwarding=1
sysctl -w net.inet.ip.fw.verbose=1
sysctl -w net.inet.ip.fw.debug=0
ipfw flush
ipfw add 100 allow ip from any to any via lo0
# Forward native SMB and NetBIOS sessions to non-privileged ports
ipfw add 200 fwd <local-ip>,1445 tcp from any to any dst-port 445 in
ipfw add 300 fwd <local-ip>,1139 tcp from any to any dst-port 139 in
# Forward NetBIOS datagrams to non-privileged ports (does not currently work)
ipfw add 400 fwd <local-ip>,1137 udp from any to any dst-port 137 in
ipfw add 500 fwd <local-ip>,1138 udp from any to any dst-port 138 in

Era lo mismo que en linux esto:
echo 1 > /proc/sys/net/ipv4/ip_forward
modprobe iptable_nat
iptables -F
iptables -t nat -F
iptables -P INPUT ACCEPT
iptables -P FORWARD ACCEPT
iptables -P OUTPUT ACCEPT
iptables -t nat -A PREROUTING -p tcp --dport 445 -j REDIRECT --to-ports 1445
iptables -t nat -A PREROUTING -p tcp --dport 139 -j REDIRECT --to-ports 1139
iptables -t nat -A PREROUTING -p udp --dport 137 -j REDIRECT --to-ports 1137
iptables -t nat -A PREROUTING -p udp --dport 138 -j REDIRECT --to-ports 1138