Publishing SMTP Mail Server in ISA Backend DMZ to ADSL Router
- From: "Surago Jones" <surago@xxxxxxxxxxxx>
- To: <isalist@xxxxxxxxxxxxx>
- Date: Wed, 12 May 2004 02:55:16 +1200
Hi All,
I have a client with that wants to implement an ISA firewall to protect
their network. Currently they are using an ADSL Router (Nokia M1122), which
includes a hub to allow workstations to connect directly to the ADSL Router.
The ISP provides a static IP which is assigned to the external interface of
the ADSL router.
We would like to continue to use the ADSL router, and configure an ISA
Server (With 2 nics) between the internal network and the ADSL router, and
also publish a Mail (SMTP) server (Sendmail/Redhat 8) that would be on the
internal network.
Configuration is as follows..
ADSL Router External IP: xxx.xxx.xxx.xxx (Statically assigned ISP)
ADSL Router Internal IP: 192.168.10.1 (Static)
ISA External IP: 192.168.10.2 (Static)
ISA Internal IP: 192.168.1.2 (Static)
Mail Server IP: 192.168.1.254 (Static)
Internal Clients: 192.168.1.0/24
With this configuration I am able to browse the web, and connect to external
(ISP) email servers from internal clients, however our Mail server does not
receive email from the outside world.
I used the Secure Mail Server wizard to create server a publishing rule to
publish the mail servers ip 192.168.1.254, to the ISA servers external ip
192.168.10.2.
Checking the Packet Filter logs I notice that all attempts to connect to
192.168.1.254 on port 25 are blocked.
I have made sure that the LAT only contains 192.168.1.0.
However I am at a loss as to why the mail isn't getting thru, as the
publishing rule exists.
Any advice or suggestions would be much appreciated. Granted an ADSL Dialup
Modem in the ISA Machine itself is easy enough to setup, however I would
like if possible to use the ADSL Router, as that way, we can put (If need
be) servers outside the ISA Firewall.
Cheers
Surago Jones
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