Route one IP address on a subnet via a different NIC from all the others

routingwindows 7

I have a windows 7 client with a wired ethernet NIC and a wireless 802.11g NIC.

The wired ethernet NIC is connected to a network switch and has subnet 192.168.0.*.

The wireless NIC is connected to a network switch and has subnet 192.168.1.*.

I also can start a VPN which accesses a network which also has subnet 192.168.0.*.

I have a linux system attached to the ethernet switch with an IP address in the 192.168.0.* range. When the VPN is connected, I can't access the linux system any more because, unsurprisingly, the packets are routed through the VPN instead of the ethernet switch.

Is there anything I can do on the W7 box to route just this single IP address corresponding to the linux box through the ethernet switch, leaving all the other 192.168.0.* addresses to be routed via the VPN?

Best Answer

You should be able to add a route to the Windows machine using the route command. Simply add the address as a /32 route, making it exit via the proper NIC.

Example:

route add 192.168.0.248 mask 255.255.255.255 0.0.0.0 if 11 metric 1

In this case "11" is an interface number, and 0.0.0.0 takes place of the gateway parameter because there is none.

Related Solutions

How to connect to two distinct networks without one being crippled

Looks like you're connecting to two different networks, both of which use DHCP and both of which are handling you a default gateway. There's no way to solve this, you have to set something manually, those DHCP servers are just giving you conflicting informations, and this just doesn't work.

You can specify which default gateway to use with this command:

ROUTE ADD 0.0.0.0 MASK 0.0.0.0 a.b.c.d

Where "a.b.c.d." is your gateway's IP address. Try to set it to your wireless network's gateway. But I don't think this will work reliably as long as you keep using DHCP on both networks at the same time.

Linux route to different subnet

The question was how to route to a different subnet on Linux. I explained in detail the situation, general replies without specifics were given.

I hacked it out on a dev server:

route add -net 10.1.200.0 (VPN ip pool) netmask 255.255.255.0 gw 172.16.1.1

and then applied to production. Works a charm and, to boot, conserves a host that would have otherwise counted against ASA base license limit of 10 hosts -- i.e. when ssh'ing into 10.1.50.1 host count increased by 1 since VPN user is considered "outside" the ASA, but when ssh'ing into the same machine on 172.16.50.1, host count remains the same since this interface has already consumed a host by virtue of its constant in/out traffic with outside world.

Best Answer

Related Solutions

How to connect to two distinct networks without one being crippled

Linux route to different subnet

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