I have a small business client who I am trying to help out with a project. Currently they have a router provided by their ISP which is doing NAT and forwarding their SMTP traffic to an internal mail server.
They want to add a PIX 501 firewall for a little extra security and VPN capabilities.
I'm going to use specific addresses (which I'm modifying slightly for anonymity) because I feel like a total idiot when it comes to configuring these PIX devices.
Right now their MX record points to 188.8.131.52 which the ISP's router points to an internal address of 192.168.1.2. The router's external WAN address is 184.108.40.206. I will ask the ISP to remove the forwarding upon installation of the new firewall.
I have available addresses of 220.127.116.11-126. I really don't wish to modify the MX record as getting the DNS changes done is always difficult in their case.
So here's what I'd like to have happen: I want ports 80,443, and 25 on external address 18.104.22.168 to forward to internal address 192.168.1.2 in the PIX. I need to know specifically how I should configure the interfaces on the PIX and how the NAT is configured.
Thanks in advance for your help.