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Short form question: Is there a way to tell an app to use the secondary NIC as a route even if it has a higher metric?

Long form question & explanation:

I have a Windows Server 2008R2 with two NIC's, each one connected to a different ISP's router. My primary ISP gives me around 5x-10x the bandwidth of the secondary, but the disadvantage is that the router's IP is not public so I can't do port forwarding for remote access (I've kind of worked around this with LogMeIn Hamachi but it's painfully slow because of the tunneling involved).

Here's the issue, I want to use the secondary NIC (which can be accessed via port forwarding) as a point of entry for remote desktop but to do this I would need the update client to use it to connect to their servers to update my IP. Can this be done? I've already checked ISP#2's router and it does not incorporate DDNS update functionality which would be ideal.

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up vote 3 down vote accepted

If that app is communicating with a separate IP space, you can create a static persistant route and specify the secondary interface for it.

If it doesn't route to a separate IP space that other apps on the server, then you're out of luck.

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This actually sounds like it would work (unless the DDNS service changed IP's). I'm going to give it a go and if it works I'll update here for posterity. Thanks for the help!! – Obi Juan Canoli Jun 23 '12 at 1:27

Some applications can be bound to specific IP addresses, but this is usually a feature of server programs, not client ones; AFAIK, there is no way (at least built into Windows) to tell an application "use this specific IP address for outgoing connections", if the application doesn't explicitly support it.

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Even if an app is bound to a specific address, it will still return traffic out the interface that the default gateway is configured on (unless you've specified an alternate route and a specific interface for it), right? – MDMarra Jun 20 '12 at 17:37
You're probably right... – Massimo Jun 20 '12 at 17:42

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