FreeBSD ipfw & natd redirect_address - freebsd

Question

I need a little help.
My rc.conf:
gateway_enable="YES"
natd_enable="YES"
natd_interface="xl0"
natd_flags="-f /etc/natd.conf"
ifconfig_xl0="inet 74.92.224.225 netmask 255.255.255.0"
ifconfig_xl0_alias0="inet 74.92.224.227 netmask 255.255.255.255"
ifconfig_xl0_alias1="inet 74.92.224.226 netmask 255.255.255.255"
ifconfig_xl0_alias2="inet 74.92.224.228 netmask 255.255.255.255"
ifconfig_xl0_alias3="inet 74.92.224.229 netmask 255.255.255.255"
ifconfig_re0="up"
ifconfig_re1="up"
cloned_interfaces="lagg0"
ifconfig_lagg0="laggproto loadbalance laggport re0 laggport re1 172.27.240.33 netmask 255.255.0.0"
firewall_client_net="172.27.0.0:255.255.0.0"
firewall_enable="YES"
firewall_logging="YES"
firewall_type="/etc/ipfw.rules"
My natd.conf:
interface xl0
use_sockets yes
same_ports yes
redirect_address 172.27.240.44 74.92.224.227
My ipfw.rules:
add 50 divert natd log ip4 from any to any via xl0
add 2000 pass all from 172.27.0.0:255.255.0.0 to 172.27.0.0:255.255.0.0 via 172.27.240.33
add 2040 deny log all from any 23 to any
add 2050 deny log all from any to any 23
add 2060 deny log all from any 111 to any
add 2070 deny log all from any to any 111
add 2080 deny log all from any 221 to any
add 2090 deny log all from any to any 221
add 2100 deny log all from any 222 to any
add 2110 deny log all from any to any 222
add 5000 pass all from any to any
Everything works fine expect coming into 74.92.224.227 does not go to 172.27.240.44 it ends up on the gateway fine but not on the LAN.
thx Thanks in advance.
Don

Answer 1

As I understand you clear, you want to NAT all packets that are coming from 172.27.240.44 to 74.92.224.227?
Also I don't think that your syntax in ipfw rules file is correct.
I would rather use ipfw kernel nat:
rc.conf (don't forget to disable LRO/TSO, because currently libalias don't work with this options correctly):
gateway_enable="YES"
firewall_enable="YES"
firewall_script="/etc/ipfw.rules"
firewall_nat_enable="YES"
firewall_logging="YES"
ifconfig_re0="up -rxcsum -txcsum -tso -lro"
ifconfig_re1="up -rxcsum -txcsum -tso -lro"
ifconfig_xl0="up -rxcsum -txcsum -tso -lro"
ifconfig_xl0="inet 74.92.224.225 netmask 255.255.255.0"
ifconfig_xl0_alias0="inet 74.92.224.227 netmask 255.255.255.255"
ifconfig_xl0_alias1="inet 74.92.224.226 netmask 255.255.255.255"
ifconfig_xl0_alias2="inet 74.92.224.228 netmask 255.255.255.255"
ifconfig_xl0_alias3="inet 74.92.224.229 netmask 255.255.255.255"
cloned_interfaces="lagg0"
ifconfig_lagg0="laggproto loadbalance laggport re0 laggport re1 172.27.240.33 netmask 255.255.0.0"
/etc/ipfw.rules:
#!/bin/sh -
fwcmd="/sbin/ipfw"
${fwcmd} -f flush
${fwcmd} -q flush
${fwcmd} -q table all flush
${fwcmd} -q pipe flush all
${fwcmd} -q queue flush all
${fwcmd} nat 1 config ip 74.92.224.227 same_ports reset deny_in
# Pass local traffic
${fwcmd} add 101 allow all from any to any via lo0
# Apply NAT on external interface
${fwcmd} add 201 nat ip from 172.27.240.44 to any out xmit xl0
${fwcmd} add 202 nat ip from any to 74.92.224.227 in recv xl0
${fwcmd} add 301 allow all from 172.27.0.0/16 to 172.27.0.0/16 via re0
${fwcmd} add 2040 deny log all from any 23 to any
${fwcmd} add 2050 deny log all from any to any 23
${fwcmd} add 2060 deny log all from any 111 to any
${fwcmd} add 2070 deny log all from any to any 111
${fwcmd} add 2080 deny log all from any 221 to any
${fwcmd} add 2090 deny log all from any to any 221
${fwcmd} add 2100 deny log all from any 222 to any
${fwcmd} add 2110 deny log all from any to any 222
${fwcmd} add 5000 allow all from any to any
Here rule 201 will map all packet coming from 172.27.240.44 to 74.92.224.227. And rule 202 will do the reverse operation.