NAT trouble

[Adam Getchell <AdamG@hrrm.ucdavis.edu>]

Hello all,

I have an extremely basic /etc/nat.conf file running on OpenBSD 3.1-stable.
I've looked through the archives, and the documentation, but I'm not
understanding where I'm going wrong. I'm not doing anything fancy, just
basic NAT: redirect all machines on a private IP address range to a public
IP, keep state, and allow established connections back in. /etc/pf.conf has
no rule restrictions either.

I do have a 2nd transparent bridging firewall, but I'm unable to ping
machines before that is reached, so I don't believe it is the issue. I have
two interfaces, ext_if is the external interface with the public_ip
assigned, int_if is the internal interface with a private_ip assigned.

>From playing around, I see that NAT is extremely sensitive to which
interface is being used.

gateway# uname -msrv
OpenBSD 3.1 GENERIC#0 i386

The active rule in /etc/nat.conf (all others are macro defs and/or comments)

nat on $ext_if from $private to any -> $public_ip

The results of pfctl -s are:

gateway# pfctl -s all
@0 pass in log all 
@1 pass out log all 
nat on ext_if from private to any -> public_ip
Status: Enabled  Time: 1032309137  Since: 1031854621  Debug: None
Bytes In IPv4: 15848304    Bytes Out: 5760821   
         IPv6: 0           Bytes Out: 0         
Inbound Packets IPv4:  Passed: 92057       Dropped: 0         
                IPv6:  Passed: 0           Dropped: 0         
Outbound Packets IPv4: Passed: 18579       Dropped: 0         
                 IPv6: Passed: 0           Dropped: 0         
States: 0
pf Counters
state searches            194922  
state inserts             18      
state removals            18      
Counters
match                     194579  
bad-offset                0       
fragment                  0       
short                     0       
normalize                 0       
memory                    0       

Any clues why this isn't working?

Thanks,

***************************	
*	Adam Getchell
AdamG@hrrm.ucdavis.edu
*	System Architect/Programmer			(530) 752-1584
*	Human Resources Information Systems
http://www.hr.ucdavis.edu/
***************************	
"Invincibility is in oneself, vulnerability in the opponent." -- Sun Tzu