Jan 7, 2011

Multiple Gateway on Different Network Interface

Hello, I’m back and writing again after doing some work. This day I want to talk about multiple gateway. A little tips but it’s good for your daily work, and helping much. My case is when I got to go to the client, and there’s no internet connection on their LAN. I have a modem to connect to the internet, but I want to connect both networks together, how am I able to do that?

Actually it’s simple enough to do that. When you look at Microsoft.com tutorial, it’s too complicated. But in my experience, it’s preety simple.

  1. Configure the default gateway for NIC with the most routes. Usually the network adapter that’s connected to internet. In my case, I don’t need to setup default gateway, coz it’s DHCP when I connect to my modem.
  2. Configure the second NIC which isn’t connected to internet a.k.a LAN, with the static IP, and DNS of your network. But please, just make the default gateway empty, just like this example picture below.
  3. Find the ID of your LAN’s Interface. To do this, open the Command Prompt and type “ROUTE PRINT” (without quotes). My LAN NIC is Realtek, and the ID is 12.
    C:\Users\Administrator>route print
    Interface List
    16...00 f1 d0 00 f1 d0 ......GlobeTrotter HSxPA - Network Interface
    14...02 00 4c 4f 4f 50 ......Microsoft Loopback Adapter
     12...00 23 5a a9 eb 5f ......Realtek RTL8102E/RTL8103E Family PCI-E Fast Ethernet NIC (NDIS 6.20)
      1...........................Software Loopback Interface 1
    13...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter
    15...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #2
    17...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #3
  4. In my LAN, all IPs are started with 10.xxx.xxx.xxx, and the gateway is This step, open Command Prompt and type this “ROUTE ADD MASK IF 12” (without quotes).
    C:\Users\Administrator>route add mask if 12

If it’s “OK!” and then nothing’s to be worried. Your job adding route is done. Now I can remote another server in LAN, and connecting to the Internet through my modem without closing another network.