Networking → Two NICS - route internet over one? LAN over other?

Hey all,

I have two NICs in my machine at work and oftentimes I need to browse to sites that would otherwise be blocked by our firewall or filter (I am an IT admin). I have an external network connection at my desk that I have setup to a 2nd NIC in my machine so I can disable/enable the NICs to connect. However, if I am working on something useing remote desktop or dameware and I need to get on the outside internet (satellite internet) I need to disabled my LAN Adapter 1, and enabled LAN Adapter 2... but then I lose connectivity to my remote desktop session.

So is there any way to have both enabled and have the PC configured to use LAN Adapter 2 specifically for any outgoing internet requests, while having LAN Adapter 1 connected as well on our internal network/domain?

Thanks,
Jon

Your a IT Admin and you don't know the ways of networking? shame on you!

In short you can't have two gateways on your PC espcially if it's a member of Active Directory. That's basic networking 101.

There is nothing you can do really accept put a bare box on the DMZ and give it very limited interent access on your firewall.

Leathal

Add the proper routes to make your machine use the other NIC for internet destinations. I do this all the time with my laptop.

you want the route command from a command prompt(windows assumed).

Well... if you were REALLY an IT admin, you would unblock what you need or adjust your content filter. My guess is neither the firewall nor the content filter is in your control and your second internet connection probably violates CorpIT policy and could get you fired.

I had to do that with a connection I needed for work. What I did I had 2 NICS in my system.

NIC 1 It had a gateway.
NIC 2 It was for work. I told all traffic from their vpn to go over this NIC and not the other one. No gateway was added. I used the route add command.

My ISA server is setup with two NICs. One NIC (external) has the gateway and is for internet. The other (internal) NIC is for all other internal and have appropriate static routes. As Leathal said, this is basic networking 101.

All my clients have their default gateway that doesn't include the ISA server. This way they don't need the static routes that ISA needs. With the ISA acting as web proxy, it subverts all configured client browser requests. The clients also have the FWC installed which acts as a winsock redirector.

Enable both nics and set your default gateway to the outside internet connection. Say your company network gives you an ip address of 10.10.10.10/8 open command prompt and enter:

route add 10.0.0.0 mask 255.0.0.0 10.10.10.10
 

And that should be all you need to do. You'll probably want to save the command in a bat file and have it run on startup.

edit:
To clarify the default gateway. A computer can only have one. So despite having a default gateway field in each connection, only one will be used. I have heard Microsoft defaults to the gateway with the lowest mac address value (Not sure if that is true). But you basically want to only fill in one default gateway and leave the default gateway blank on the other interfaces. Filling in a default gateway on all the interfaces means you have no idea which one Microsoft is going to use.