IPNAT / IPF / rdr issue

[Andy Sutcliffe]

I am having problems accessing internal resources (such as a web
server) from other internal clients when going from internal client ->
public address -> internal resource.  For example, when I attempt to
reach 'mydomain.com' from client machine X, the connection is refused
(I am of course, able to reach the web server through the internal
IP), however, I am able to access the web server via that URL from an
external network.  I have 'mydomain.com' pointed towards the external
IP of my gateway which in turn relays it to the internal web server. 
I have included the pertinent contents of /etc/ipnat.rules as well as
my /etc/ipf.conf file.  I am at a loss at this point...can anyone
point me in the right direction ?

Thanks in advance,
  - andy ( andy dot sutcliffe at gmail dot com)

Gateway:
  OS:FreeBSD 5.4
  Firewall: IPFilter
  Port Forwarding: IPNAT
  External eth: dc0
  Internal eth: ed0 (10.0.0.0)

Web Server
  OS: FreeBSD 5.4
 WWW: Apache 2.0

Client Machine(s)
  OS: Windows XP, FreeBSD, Linux

I have the following in /etc/ipnat.rules:

# innernet
map dc0 10.0.0.0/16 -> 0.0.0.0/32 portmap tcp/udp 40000:65000
map dc0 10.0.0.0/16 -> 0.0.0.0/32

# www
rdr dc0 0.0.0.0/0 port 80 -> 10.0.0.3 port 80

I have the following in /etc/ipf.conf:
#################################################################
# No restrictions on Inside LAN Interface for private network
# Not needed unless you have LAN
#################################################################

pass out quick on ed0 all
pass in quick on ed0 all

#################################################################
# No restrictions on Loopback Interface
#################################################################
pass in quick on lo0 all
pass out quick on lo0 all

#################################################################
# Interface facing Public Internet (Outbound Section)
# Interrogate session start requests originating from behind the
# firewall on the private network
# or from this gateway server destine for the public Internet.
#################################################################

# Allow out access to my ISP's Domain name server.
# xxx must be the IP address of your ISP's DNS.
# Dup these lines if your ISP has more than one DNS server
# Get the IP addresses from /etc/resolv.conf file
pass out quick on dc0 proto tcp from any to 67.43.192.6 port = 53
flags S keep state
pass out quick on dc0 proto udp from any to 67.43.192.6 port = 53 keep state
pass out quick on dc0 proto tcp from any to 137.118.1.33 port = 53
flags S keep state
pass out quick on dc0 proto udp from any to 137.118.1.33 port = 53 keep state

# Allow out access to my ISP's DHCP server for cable or DSL networks.
# This rule is not needed for 'user ppp' type connection to the
# public Internet, so you can delete this whole group.
# Use the following rule and check log for IP address.
# Then put IP address in commented out rule & delete first rule
pass out quick on dc0 proto udp from any to 67.43.192.6 port = 67 keep state


# Allow out non-secure standard www function
pass out quick on dc0 proto tcp from any to any port = 80 flags S keep state
pass out quick on dc0 proto tcp from any to any port = 81 flags S keep state

# Allow out secure www function https over TLS SSL
pass out quick on dc0 proto tcp from any to any port = 443 flags S keep state

# Allow out send & get email function
pass out quick on dc0 proto tcp from any to any port = 110 flags S keep state
pass out quick on dc0 proto tcp from any to any port = 25 flags S keep state

# Allow out Time
pass out quick on dc0 proto tcp from any to any port = 37 flags S keep state

# Allow out nntp news
pass out quick on dc0 proto tcp from any to any port = 119 flags S keep state

# Allow out gateway & LAN users non-secure FTP ( both passive & active modes)
# This function uses the IPNAT built in FTP proxy function coded in
# the nat rules file to make this single rule function correctly.
# If you want to use the pkg_add command to install application packages
# on your gateway system you need this rule.
pass out quick on dc0 proto tcp from any to any port = 21 flags S keep state

# Allow out secure FTP, Telnet, and SCP
# This function is using SSH (secure shell)
pass out quick on dc0 proto tcp from any to any port = 22 flags S keep state

# Allow out non-secure Telnet
pass out quick on dc0 proto tcp from any to any port = 23 flags S keep state

# Allow out FBSD CVSUP function
pass out quick on dc0 proto tcp from any to any port = 5999 flags S keep state

# Allow out ping to public Internet
pass out quick on dc0 proto icmp from any to any icmp-type 8 keep state

# Allow out whois for LAN PC to public Internet
pass out quick on dc0 proto tcp from any to any port = 43 flags S keep state

# Block and log only the first occurrence of everything
# else that's trying to get out.
# This rule enforces the block all by default logic.
block out log first quick on dc0 all

#################################################################
# Interface facing Public Internet (Inbound Section)
# Interrogate packets originating from the public Internet
# destine for this gateway server or the private network.
#################################################################

# Block all inbound traffic from non-routable or reserved address spaces
block in quick on dc0 from 192.168.0.0/16 to any    #RFC 1918 private IP
block in quick on dc0 from 172.16.0.0/12 to any     #RFC 1918 private IP
# block in quick on dc0 from 10.0.0.0/8 to any        #RFC 1918 private IP
block in quick on dc0 from 127.0.0.0/8 to any       #loopback
block in quick on dc0 from 0.0.0.0/8 to any         #loopback
block in quick on dc0 from 169.254.0.0/16 to any    #DHCP auto-config
block in quick on dc0 from 192.0.2.0/24 to any      #reserved for docs
block in quick on dc0 from 204.152.64.0/23 to any   #Sun cluster interconnect
block in quick on dc0 from 224.0.0.0/3 to any       #Class D & E multicast

##### Block a bunch of different nasty things. ############
# That I do not want to see in the log

# Block frags
block in quick on dc0 all with frags

# Block short tcp packets
block in quick on dc0 proto tcp all with short

# block source routed packets
block in quick on dc0 all with opt lsrr
block in quick on dc0 all with opt ssrr

# Block nmap OS fingerprint attempts
# Log first occurrence of these so I can get their IP address
block in log first quick on dc0 proto tcp from any to any flags FUP

# Block anything with special options
block in quick on dc0 all with ipopts

# Block public pings
block in quick on dc0 proto icmp all icmp-type 8

# Block ident
block in quick on dc0 proto tcp from any to any port = 113

# Block all Netbios service. 137=name, 138=datagram, 139=session
# Netbios is MS/Windows sharing services.
# Block MS/Windows hosts2 name server requests 81
block in log first quick on dc0 proto tcp/udp from any to any port = 137
block in log first quick on dc0 proto tcp/udp from any to any port = 138
block in log first quick on dc0 proto tcp/udp from any to any port = 139
block in log first quick on dc0 proto tcp/udp from any to any port = 81

# Allow traffic in from ISP's DHCP server. This rule must contain
# the IP address of your ISP's DHCP server as it's the only
# authorized source to send this packet type. Only necessary for
# cable or DSL configurations. This rule is not needed for
# 'user ppp' type connection to the public Internet.
# This is the same IP address you captured and
# used in the outbound section.
pass in quick on dc0 proto udp from 67.43.192.6 to any port = 68 keep state

# Allow in standard www function because I have apache server
pass in quick on dc0 proto tcp from any to any port = 80 flags S keep state
pass in quick on dc0 proto tcp from any to any port = 81 flags S keep state

# Allow in secure FTP, Telnet, and SCP from public Internet
# This function is using SSH (secure shell)
pass in quick on dc0 proto tcp from any to any port = 22 flags S keep state

# Allow in non-scure FTP access to file server (bombadil)
pass in quick on dc0 proto ftp from any to 10.0.0.2 port = 21 flags S keep state
pass in quick on dc0 proto ftp from any to 10.0.0.2 port = 20 flags S keep state
pass out quick on dc0 proto ftp from 10.0.0.2 to any port = 20 flags S
keep state

# Block and log only first occurrence of all remaining traffic
# coming into the firewall. The logging of only the first
# occurrence stops a .denial of service. attack targeted
# at filling up your log file space.
# This rule enforces the block all by default logic.
block in log first quick on dc0 all
################### End of rules file #####################################