Not sure if that was the link you really wanted
Always a possibility.
I agree that having a dual-WAN router arbitrate the two external connections will do the trick. But I didn't think that was the question being asked.
I interpreted the question to be whether it was possible to hook both the EDGE and standard broadband internet
connections directly into the server
and have that work reliably.
The reason I interpreted it that way was because I've seen numerous cases where a server arrives equipped with three NICs which someone decides to set up it as 2 externals + 1 internal ("to increase Internet throughput"); next plugs the external facing cards into two
different internet connections, and then wonders what the problem is. Especially if (or more likely when) DNS settings are also misconfigured - usually by having the external adapter's DNS setting not point to itself and wind up having the AD 'glom' onto it as a result
And to your point about isolating services using one server with multiple interfaces, I also agree. I often do that myself. Perhaps "multihoming" wasn't the best choice of terms when I probably should have said "bridging" or "spanning" and clarified I was talking about the external
Addendum: If DNS is set up properly
is a pretty big 'if' from what I've seen. FWIW I discover DNS configuration problems in about a quarter of the Windows servers I look at. What is it about server DNS settings that some people feel the need to be constantly screwing around with them?