Ubuntu – How to set routes for the vpn connection

internetroutingvpnvpnc

In my previous question I was asking about setting up vpnc connection. I've installed network-manager-vpnc so now I can configure all this stuff right from network manager gui.

I have got this pretty picture from related topic:

I have got this pretty picture from related topic:

So the question is how to figure out what Address, Netmask and Gateway should I use to pass ONLY this trafic through vpn.

As a basis I have got an ip and a port of the external service which I want to use through vpnc. So inernet and other traffic should go as always through ethernet or wifi.

  • External ip: 10.20.30.40
  • Port: 1433 (this is sql server actually)

Best Answer

  1. Now click on the “IPv4 Settings” tab and click “Routes…”
  2. Click “Add” and in the “Address” box, enter the IP address of the machine you which to access. For our XYZ server, this is “203.0.113.3”. In the “Netmask” box enter “255.255.255.255” (to indicate we only want this single IP address). Leave the Gateway and Metric boxes empty.
  3. Select “Use this connection only for resources on its network”
  4. Click “Ok” on the “Editing IPv4 routes” box
  5. Click “Save…”

Copy from http://blog.rac.me.uk/2013/10/20/linux-setting-up-a-vpn-to-only-route-specific-ip-addresses/

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