(ipfw, ipfw nat, ipfw fw)

Необходимые опции ядра

options         IPFIREWALL
options         IPFIREWALL_FORWARD
options         IPFIREWALL_NAT

Скрипт запуска:

#!/bin/sh

IPFW="/sbin/ipfw"
EXT_IP="92.242.110.42"
ISP_IP="92.242.110.41"
NAT_ID=22
TABLE_NUM=34
REDIRECT_IPS="10.0.0.0/24"

${IPFW} nat ${NAT_ID} config ip ${EXT_IP} log
for ip_mask in ${IPS} ; do
  ${IPFW} table ${TABLE_NUM} add 92.242.110.42 ${NAT_ID}
done;

${IPFW} 60015 add fwd ${ISP_IP} ip from ${EXT_IP} to any