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So here's the setup.

At my company we use a large VPN with several different subnets, and apparently the wireless routers have access to some of the hosts on the VPN but not all, while the ethernet ports (connected to a switching station somewhere in the building) are connected to a different set of hosts.

I was wondering if there was a way to tell any application to use a particular NIC instead of the default chosen by the OS, and possibly to setup rules for it, for instance, a way to tell Chrome to use the wireless adapter and Firefox to use the ethernet adapter.

I know that applications can be programmed to do this and I know that any machine with multiple NICs is physically capable of such a thing, I just don't know how to control it.

Here's an ipconfig /all showing both NICs and the separate subnets they are connected to:

Windows IP Configuration

   Host Name . . . . . . . . . . . . : yourmothersahost
   Primary Dns Suffix  . . . . . . . :
   Node Type . . . . . . . . . . . . : Hybrid
   IP Routing Enabled. . . . . . . . : No
   WINS Proxy Enabled. . . . . . . . : No
   DNS Suffix Search List. . . . . . : example.com

Ethernet adapter Local Area Connection:

   Connection-specific DNS Suffix  . : example.com
   Description . . . . . . . . . . . : Intel(R) 82566MM Gigabit Network Connection
   Physical Address. . . . . . . . . : 00-1E-EC-90-96-28
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   Link-local IPv6 Address . . . . . : fe80::80a3:cb35:48c0:ae43%12(Preferred)
   IPv4 Address. . . . . . . . . . . : 10.10.29.69(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Lease Obtained. . . . . . . . . . : Thursday, November 03, 2011 12:36:16 PM
   Lease Expires . . . . . . . . . . : Sunday, November 06, 2011 3:24:29 PM
   Default Gateway . . . . . . . . . : 10.10.29.1
   DHCP Server . . . . . . . . . . . : 10.10.16.45
   DHCPv6 IAID . . . . . . . . . . . : 318775020
   DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-14-51-42-35-00-1E-EC-90-96-28
   DNS Servers . . . . . . . . . . . : 8.8.8.8
                                       8.8.4.4
   Primary WINS Server . . . . . . . : 10.10.16.42
   Secondary WINS Server . . . . . . : 10.10.40.45
   NetBIOS over Tcpip. . . . . . . . : Enabled

Wireless LAN adapter Wireless Network Connection:

   Connection-specific DNS Suffix  . : example.com
   Description . . . . . . . . . . . : Broadcom 802.11a/b/g WLAN
   Physical Address. . . . . . . . . : 00-21-00-40-D5-70
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   Link-local IPv6 Address . . . . . : fe80::a0b2:9b70:3b19:47d0%11(Preferred)
   IPv4 Address. . . . . . . . . . . : 10.10.55.27(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.252.0
   Lease Obtained. . . . . . . . . . : Thursday, November 03, 2011 12:36:29 PM
   Lease Expires . . . . . . . . . . : Thursday, November 03, 2011 6:47:35 PM
   Default Gateway . . . . . . . . . : 10.10.52.1
   DHCP Server . . . . . . . . . . . : 192.168.254.254
   DHCPv6 IAID . . . . . . . . . . . : 184557824
   DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-14-51-42-35-00-1E-EC-90-96-28
   DNS Servers . . . . . . . . . . . : 10.10.16.42
                                       10.10.16.45
   Primary WINS Server . . . . . . . : 10.10.16.42
   Secondary WINS Server . . . . . . : 10.10.40.45
   NetBIOS over Tcpip. . . . . . . . : Enabled

Tunnel adapter isatap.example.com:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . : example.com
   Description . . . . . . . . . . . : Microsoft ISATAP Adapter
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes

Tunnel adapter Local Area Connection* 11:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes
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A method that is surely going to work is to run a SOCKS proxy locally and set it to only use one specific IP/network adapter. You can then set the different applications to use different proxies.

I used to do this a lot when I only want specific programs to access resources through a VPN connection.

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Windows 7 Pro (not sure about Home) lets you "sort of" do this in the Advanced Firewall settings.

After creating an application-specific outgoing rule, you can configure the advanced properties to limit the connection to specific connection types such as "Local Area Network" or "Wireless Networks." I don't know if there's a way to specify the actual network device, as may be the case when multiple wired adapters are present.

I haven't actually tested this.

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