OpenVPN: Providing a Secure Connection for Your Users

Tweaking ICS

Continued from Page 1.

So now you have your clients pushing all of their data at your server expecting it to handle all of the duties a service provider would be responsible for. That'd usually be no small task and it'd require quite a bit of figuring out on your part if you wanted custom solutions for each and every protocol your users might require.

Thankfully Microsoft's Internet Connection Sharing is able to handle a good bulk of the traffic your server is likely to encounter from your clients. The simple act of enabling ICS and allowing the program to handle most of the common services will give your clients access to a bulk of the web services they'll need.

In order to enable ICS you'll have to open up the properties page for the connection, on your server, that's connected to your Internet facing network. You'll likely find it under the Network Connections option in the Control Panel. The advanced tab will allow you to enable ICS and some additional settings/services you might like to allow your clients to have access to.

You're likely thinking that third-party connection sharing applications can perform the same functions as ICS. However, for the sake of simplicity, we're sticking with what's freely available with most Windows installations.

Once you've restarted your OpenVPN server's session after all of these changes the simple way to test if all of this has worked would be to load up a IP Address lookup website (http://whatsmyip.org/). The result should match the actual IP Address of your server, confirming that the server is fetching and transferring files to your client correctly.

Something you're likely to run into when tinkering with ICS settings is OpenVPN's apparent unwillingness to work on your server, spitting out "Warning: route gateway is not reachable on any active network adapters" errors. Windows doesn't seem to play nice with OpenVPN on occasion but the prowess of the Internet at problem solving has come up with this gem of a forum thread with a working solution should things head south on your server.

The following commands in a command prompt and a subsequent reboot should give you a working configuration again:

netsh int ip reset logfile.txt
netsh winsock reset catalog

If everything went smoothly, your clients should have a safe and secure method of browsing the Internet at large and use the various the web-based applications they require. However, there are as many use cases as there are corporate networks There is more to OpenVPN which we'll be sure to cover in future installments.