From: Fairview Heights, IL, USA
I have a client (Company A) who is running ISA Server 2004 Enterprise Edition. They presently have one ISP (ISP A) and one internal network (Private LAN A) so the configuration is relatively simple. Another company (Company B) has recently moved into their building and brought with them their own internal network (Private LAN B) and their own ISP (ISP B). Company B does not have an ISA Server. They just use a basic brain-dead NAT router.
The two companies are business partners. They each need to access data in the other's network. They used to do this via a site-to-site VPN between the ISA Server and the brain-dead NAT router but it was very slow and ate up most of their Internet bandwidth. They could obviously continue this practice, but it would be ridiculous since they are now in the same building. They've thought about just combining their networks, but there are several reasons why this is not acceptible. They also would rather not go down to just one Internet connection. So here's what we want to do...if it's possible with ISA Server 2004 Enterprise Edition.
We'd like to have four NICs in the ISA Server, one for each Private LAN and one for each ISP connection. Setting up routing and security between the two Private LANs is simple. However, we'd like Company A to continue to use ISP A as their primary Internet route and Company B to continue to use ISP B as their primary Internet route. In the event that either ISP should be unreachable, we'd like both companies to be able to share the remaining ISP (even if it requires a manual change on the ISA Server...we don't necessarily expect automatic fail-over, but it would be nice).