How can I add a ipfw forward rule to little snitch?
Since ipfw is also removed in Yosemite the solution is to use pf

create a file in /etc/pf.anchors/

e.g. com.myapp

rdr pass on lo0 inet proto tcp from any to any port 80 -&gt; 127.0.0.1 port 8080


NOTE: Add a trailing line break. Otherwise pf will say you have a syntax error.

edit /etc/pf.conf add right after rdr-anchor "com.apple/*":

rdr-anchor "myapp"


and after load anchor "com.apple" from "/etc/pf.anchors/com.apple":

load anchor "myap" from "/etc/pf.anchors/com.myapp"


NOTE: Add a trailing line break. Otherwise pf will say you have a syntax error.

Next, reload the rules into pf by running sudo pfctl -f /etc/pf.conf

Finally, enable pf by running sudo pfctl -e

Source: https://github.com/basecamp/pow/issues/452