How to direct SMTP traffic to Exchange Server with 2 NICs behind a Rou

[saintpi]

I need to create access to a new Exchange Server. The server has 2 network cards (NICs). One with internal IP and the other with a public IP. My network is as follows:- Internet <--> Cisco Router <--> PIX 515E <--> Switch --> LAN. The Router has a public IP on the outside interface and a private IP on the inside. The PIX has private IPs on both interfaces on different subnets.
The router and the pix both have only 2 interface ports. I cannot create a DMZ on a separate interface.
How do I safely connect the Exchange Server to the network? Do I physically connect the cables from both NICs to the LAN? Or do I have to install a switch between the Router and the PIX and then connect the Public NIC to the switch? How do I route traffic through the Router and the PIX to the Mail Server? Thanks.

 

[unclerico]

why does your exchange server need a public ip attached to a NIC??

I hate all Uppercase... I don't want my groups to seem angry at me all the time! =)
- ColdFlame (vbscript forum)

 

[FloDiggs]

Sounds like you need to set up an access list and a static translation to allow port 25 through your pix to your Exchange server.

For the static translation, something similar to this should work:

static (inside,outside) tcp interface smtp <insiert-exchange-IP-here> smtp netmask 255.255.255.255

For the access lists, something like this should work:

access-list outside_in permit tcp any interface outside eq smtp

You should NOT try to plug your exchange server in with two NICs, one inside the network and one out. That would completely defeat the purpose of your firewall. Only use the NIC currently configured with an internal IP.