Kernel Config for NAT

[n j]

> That's actually a good question considering the lack of documentation.  If
> that works then great, but one wonders what the ipfw_nat modules is for?
> looks like it's tied into libalias apparently a replacement for natd.

Here's my kernel configuration:

[--snip--]
options         IPFIREWALL              # enable ipfw firewall
options         IPDIVERT                # for divert funcionality -
not really required
options         IPFIREWALL_FORWARD      # for ipfw forward functionality
options         IPFIREWALL_NAT          # for in-kernel nat
options         LIBALIAS                # req'd by ipfirewall_nat
[--snip--]

If I'm to trust the comment I wrote quite a while ago, IPDIVERT is not
necessary. Also, IPFIREWALL_FORWARD is not really needed for NAT, this
is specific to my setup. So, basically that leaves IPFIREWALL,
IPFIREWALL_NAT and LIBALIAS as the necessary tweaks in kernel conf for
NAT to work.

Note, this configuration enables the in-kernel NAT which is
(relatively) recent addition to FreeBSD. You turn it on like this:

ipfw nat 123 config ip 192.168.0.123 log
ipfw add nat 123 all from any to any

In my experience, it works pretty well and I consider it a big
improvement over running natd and diverting packets to it.

Regards,
-- 
Nino