I currently have a Cisco 1841 with the two embedded NIC's, one is for inside and the other is for the outside. The outside has five staic IP's and we have some one to one NAT's and ports mapped to inside devices. We need to add a second WAN for redundancy, the new connection will have static IP's as well. We want normal web brousing and VPN traffic to use the second WAN connection and if it goes offline all the traffic should use the original WAN. Also the original WAN will be used primarily for server traffic (i.e. smtp, web.....).
When I added the new HWIC and configured it for the backup ISP, I was able to browse the internet but all traffic stopped flowing for the original WAN, no smtp or other traffic at all.
What am I doing wrong, is there a way to have primary web going through my second WAN and if it goes offline all traffic failover to the primary WAN? Also can both WAN connections have NAT'ing to inside devices, even NAT'ing of the same port number like 25?