Linux with NAT -- Also needing web access to postgres on same box

I am using RedHat 7.3 with iptables 1.2.6a, Apache 1.3.27 compiled with PHP 4.2.3 and mod_perl 1.27, and running postgresql.

I want to access data stored within postgresql from a php script. The exact line used for connection to postgresql is this:
$database = pg_connect ("host=localhost user=postgres dbname=xbase");

If I temporarily reset the NAT process all is good, i.e. a web page displays with the data correctly extracted from postgresql.

Alas, when the system is functioning in its normal, NAT, mode I get the following error message rather than the correct web page display:

===== Begin web error message =======
Warning: pg_connect() unable to connect to PostgreSQL server:
could not connect to server: Connection timed out Is the server running on host localhost and accepting TCP/IP connections on port 5432? in /usr/www/site.admin/htdocs/sasixp/DPHS.php on line 21
An error occured with the connection.
===== End web error message =======

My thought is that a few correct addition(s) to my iptables script should allow the internal connection to postgresql.

Unfortuneately, I don't yet have the skill to determine what those line(s) should be.

Any help and or suggestions would be very much appreciate and, I'm sure, instructive.
THANKS

====== Begin current script for NAT ========
# Nat Reset
/sbin/iptables --flush INPUT
/sbin/iptables --policy INPUT ACCEPT
/sbin/iptables --flush FORWARD
/sbin/iptables --policy FORWARD ACCEPT
/sbin/iptables --flush OUTPUT
/sbin/iptables --policy OUTPUT ACCEPT

/sbin/iptables --table nat --flush PREROUTING /sbin/iptables --table nat --policy PREROUTING ACCEPT /sbin/iptables --table nat --flush POSTROUTING /sbin/iptables --table nat --policy POSTROUTING ACCEPT /sbin/iptables --table nat --flush OUTPUT /sbin/iptables --table nat --policy OUTPUT ACCEPT

# Nat SetUp

/sbin/iptables   --table nat  --flush  POSTROUTING
/sbin/iptables   --table nat  --policy POSTROUTING DROP
/sbin/iptables   --table nat   \
                        --append POSTROUTING \
                        --source 172.16.0.0/16 \
                        --jump SNAT \
                        --to 204.48.xxx.yyyI

echo 1 > /proc/sys/net/ipv4/ip_forward
====== End current script for NAT ========

"Experience is not what happens to you, it
is what you do with what happens to you"

       -- Aldous Huxley (1894-1963)

Ashe Coutts ([email protected])
805.963.7751 Ext 260
Fax 805.884.1557