SV: nat/outbound traffic not passing in pf on FreeBSD 6.1

[Jeffrey Williams]

ok I went ahead and opened up the lo, it still does not work.  Adding 
pass to the nat statement causes all nated packets to bypass all of the 
other filter rules, this is not acceptable.  once again the ruleset 
works fine on OpenBSD, so what is different about pf on FreeBSD.

I do not believe the problem is in the rules, I repeat this rule set 
works 100% in pf on OpenBSD, I have not found any documentation that 
states the pf on FreeBSD interprets rules differently than on OpenBSD. 
So either there is a difference that I have not found, if so can 
somebody tell me what that difference is? or there is a bug in the 
FreeBSD pf code, if so does anybody know what it is, and if there is a 
work around.

The other possibility is I am missing a compile time setting or a kernel 
setting, if so does anybody know what it might be?

Thanks,
Jeff

Jon Simola wrote:
> On 7/26/06, Jeffrey Williams <jeff at sailorfej.net> wrote:
> 
>> I am not running anything that is trying to use the loopback interface
>> on this box.
> 
> Blocking traffic on the loopback will cause many odd problems. Always use
> set skip on lo
> 
>> The following rule passes traffic in on the internal interface, "pass in
>> on $iif inet from $inwr to any keep state", and there is no rule
>> blocking traffic out on the internal interface.
> 
> The problem here is that the NAT translation of the packet takes place
> before pass and block rules are processed. NAT'ed packets appear to be
> incoming on the internal interface with an IP address of the external
> interface. So you can pass all traffic on the internal interface, or
> get a little fancier and use tags with NAT:
> 
> nat on $ext_if from $int_if:network to !$int_if:network tag NAT -> 
> ($ext_if:0)
> pass all tagged NAT keep state
> 
> Or for the minimal ruleset:
> 
> nat pass on $ext_if from $int_if:network to !$int_if:network -> ($ext_if:0)
>