I have had two WVC80N cameras running on the same network for years using one DynDNS address to reach them. The router does the DynDNS address reporting.
I set different static IPs for each camera on Basic tab, and one camera to port 1024 and the other to port 1025 on the Options tab. The router needs to have port forwarding configured to send each port to the respective camera's static IP address. Then I reach them through the URL: [myname]:dyndns.org:1024, and :1025 respectively.
Works fine ... as long as the cameras are up and the browser is compatible. That's another story.