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Summary: I need to setup a single PC with two NICs - to access a service on LAN 2

NIC 1 - Data network, web access. Range: 192.168.1.x Sub: Gateway:

NIC 2 - No Web access Range: 192.168.1.x Sub: Gateway:

What im trying to do:

I need the primary NIC to run as is, with all traffic running through it for LAN and WAN. NIC2 is purely used to telnet into for a data stream.

Problems and question:

  • Cannot merge the LANs as LAN 1 is for data and LAN 2 is purely for the voice system with a voice switch.
  • would not like to change address ranges, far too much work involved and business runs 24/7

Q: If I leave NIC 1 as is, working fine and well. If I plug in NIC 2 to LAN 2, can i setup a route so that if is telnetted etc, the PC will select NIC 2 and probe the IP appropriately. Obviously I will ensure that is not used on LAN 1

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possible duplicate of Configure routing between same network address – theotherreceive Jul 4 '11 at 16:52
Mike, many thanks for that, exactly what I was looking for and makes complete sense - I would like to accept that answer but I couldn't log into my registered account from work! – Douglas Rae Jul 4 '11 at 18:37
Are you really going to bridge the two networks? – SpacemanSpiff Jul 4 '11 at 19:08

You should be able to do what you want.

You will need to assign different IP Addresses to NIC1 and NIC2, and ensure that the NIC2 address does not exist on LAN1 and vice-versa, also ensuring that LAN2-HOST1 ( does not exist on LAN1.

You then need to set the default route to via NIC1, and add a static route for LAN2-HOST1 via NIC2.

You don't say what operating system is on your PC, on windows you can do:

netsh interface ipv4 add route "LAN2_INTERFACE_NAME" LAN2_INTERFACE_IP

If you add the keyword


To the end of that command, the change will be effective across reboots.

You can achieve similar on Linux if required ...

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