4 trap 'echo "$0:$LINENO:error: \"$BASH_COMMAND\" returned $?" >&2' ERR
9 /sbin
/iptables
-t nat
$cmd PREROUTING
-i eth0
-p tcp
-m tcp
--dport $port -j DNAT
--to-destination 10.8.0.4:$port
16 do-forward
-A ${ports[@]}
19 do-forward
-D ${ports[@]}
22 echo "$0: error: expected 1 argument of start or stop"