configuring a leased line server

[Andre Grove]

Hello there

How do would I go about configuring FreeBSD 5.1 to be a leased line 
server? Basically a mail server and gateway.
I can get a null modem to connect and obtain an IP address. But I am 
only able to access the machine from outside if there is a 
"default_router" for my network.

Here is my rc.conf file:

#defaultrouter="192.168.1.4"
hostname="bsd.adept.co.za"
ifconfig_rl0="inet 192.168.1.145  netmask 255.255.255.0"
inetd_enable="NO"
kern_securelevel_enable="NO"
linux_enable="YES"
saver="daemon"
sendmail_enable="YES"
sshd_enable="YES"

network_interfaces="rl0 ppp0"
router_enable="NO"

gateway_enable="YES"
firewall_enable="YES"
firewall_type="OPEN"
natd_enable="YES"
natd_interface="ppp0"
natd_flags=""

I cannot ping any external addresses from the box.
I have already compiled my kernel for IP forwarding as stated in the 
handbook.
The other thing, is that my connect script doesn't run at startup, even 
though i have put it in /usr/local/etc/rc.d/ . But that is minor for now.

What have I done incorrectly and what else do i still need to do?

Thanks

Andre