UNIX for Dummies Questions & Answers

Hi there,

Believe it or not, the word VPN doesn't give any search result in the forum.

I'm trying to get started with VPN.
I'm currently in the process of setting up a server.
I found a lot of howtos on the web.

There's still one thing that I'm not sure of.
My plan is to setup the VPN on an online server.
I mean a dedicated server hosted at OVH with a public IP like 91.121.101.109.
Then, I want several servers, hosted in various offices (behind internet boxes) to connect to the main server and thus becoming accessible to one each other.

I've already prepared every office to be in a different network range (10.0.1.X, 10.0.2.X, 10.0.3.X, etc.) to avoid conflicts.
But then how can I assign the address say 10.0.0.1 to the main server given that it only has one NIC with IP 91.121.101.109.

Thanks for your help
Santiago

Depends on the VPN.

Also depends on the kind of server.

You've given no details.

We use OpenVPN at our office to join Linux servers together over a VPN. It uses a special driver called the "universal tun/tap interface" which acts like a virtual network card that's completely software controlled. Encrypted VPN traffic received over port 1194 on the ordinary network is converted into incoming network traffic on the tun0 interface, and vice versa, with the OpenVPN daemon converting between the two.

If you want the VPN to connect to real IPs on the other end I think this would be OpenVPN's bridged mode, which generally isn't recommended and usually isn't used. Usually the traffic is completely virtual.

Hi Corona688,

That's right, I didn't give much details. Actualy, I'm a real beginner in the subject and I don't even know what I'm talking about. But I'm reading a lot and learning fast ;o)

I indeed plan to use OpenVPN. I also read about the "tun/tap" virtual interface.
If I understand well, I can give any address in the following directives in /etc/pptpd.conf because it's all virtual and not related to the physical NIC :

Code:

# cat /etc/pptpd.conf
...
localip 10.5.1.3
remoteip   10.5.1.241-246
...

I'm currently reading this howto about How to setup a dedicated PPTP VPN Server at your home office or main office. Am I going in the right direction?

Thanks for your help.
Santiago

pptpd is not openvpn. openvpn is openvpn, pptpd is pptpd. I think you're reading the wrong tutorial.

If you use the How-To on the OpenVPN website, they do make things quite easy, just make sure you set it up in Routed mode.

2 things to watch for:

In the OpenVPN server config file, you need to enable "client-to-client" and make sure you push routes to all clients.

In the kernel of the server, you need to enable IPv4 forwarding.

Also make sure you open the Firewall port 1194 on the server.