I’m having a problem with my ISP. … The ISP says it cannot join two IP addresses with one MAC address. Any suggestions?
I’m having a problem with my ISP. My network has a cable modem connected to a firewall (WAN port), then to a switch, which connects to a Web and e-mail server. I have two public IP addresses, one for Internet and one for the Web and mail server. The firewall (3Com Office Connect Firewall DMZ) has only one media access control address. The ISP says it cannot join two IP addresses with one MAC address. Any suggestions?
With your infrastructure and ISP you would use only one public IP address attached to the firewall WAN port.
You would then configure the 3Com firewall box to forward incoming Web (TCP Port 80) and e-mail (TCP Port 25) traffic to your Web/mail server on the demilitarized zone interface of your firewall box (as well as provide firewall and network address translation services for your LAN).
Using both of the public IP addresses would require placing the Web/mail server between the cable modem and the firewall WAN connection.
This would place the Web/mail server directly on the Internet without the benefit of firewall protection, and might not be supported by the ISP, depending on the cable modem service subscription.
