I received static IP addresses from AT&T. They gave me two sets, a public WAN and a public LAN (these are obviously not the real IPs):
Subnet Mask: 255.255.255.252
Useable IPs: 184.108.40.206/245
Subnet Mask: 255.255.255.248
The office consists of a DSL modem ->Linksys WRT54G router -> SBS 2003 server ->workstations
Additionally, the SBS 2003 server is a mail server with an MX record and linked to a LAN IP. I need to be able to see the server from the Internet (ping it, send mail, remote access, etc). SBS has a dual NIC and from what I understand is supposed to be setup with one internal NAT network and one external ISP network.
Diagram below is how I have it setup now.
My problem is that I cannot see the server from the Internet. I need the Linksys router for office wireless connectivity (printers, notebooks, etc). AT&T will not allow the LAN IPs to be on their network and they control routing from the 89.x subnet to resolve to 79.x. I can ping both 89.x IP addresses as well as the Linksys LAN side (220.127.116.11). But, even putting the SBS server IP (18.104.22.168) in the DMZ does not allow me to see it from the Internet. Port forwarding also doesnt work. Am I missing something?