If you’re looking to set up a VPN (virtual private network) server on Debian Linux, there are a few things you’ll need to do. In this article, we’ll walk you through the process of setting up a PPTP VPN server on Debian Linux. First, you’ll need to install the required packages. On Debian Linux, this includes the libpcap library and the openvpn package. Once these packages have been installed, you can begin setting up your VPN server. To start off, create a directory in which to store your VPN configuration files. Next, copy the openvpn configuration file to this new directory. The openvpn configuration file contains all of the information necessary to set up your VPN server. Next, you’ll need to configure your network interface in order to allow traffic through your VPN tunnel. To do this, open the /etc/network/interfaces file and add an entry for your virtual network interface. In our example, we’re using eth0 as our virtual network interface. You should also specify which IP address range should be allowed through the tunnel and which protocols should be allowed through it (in our case, we’re allowing all traffic). Finally, you’ll need to enable IP forwarding on your router in order for traffic destined for your virtual network interface to reach your VPN server. Now that everything is setup, it’s time to start configuring your VPN client software. To do this, first install the libpcap library on your computer (if it isn’t already installed). Next, download and install the openvpn client software onto your computer. Finally, connect to your virtual network interface using the openvpn client software and configure it as desired (in our example we’re using localhost as our remote host). ..
VPN-ing into your server will allow you to connect to every possible service running on it, as if you were sitting next to it on the same network, without individually forwarding every port combination for every service you would like to access remotely.
Using a VPN connection also has the upshot of, if desired, granting access to other computers on the network as if you where in it locally from anywhere across the internet.
While not the most secure of the VPN solutions out there, PPTP is by far the simplest to install, configure and connect to from any modern system and from windows specifically as the client is a part of the OS since the XP days and you don’t need to mess with certificates (like with L2TP+IPsec or SSL VPNs) on both sides of the connection.
Did i get you interested? then let’s go :)
Preface
You will need to forward port 1723 from the internet to the server to enable the connection (not covered here). You will see me use VIM as the editor program, this is just because I’m used to it… you may use any other editor that you’d like.
Server Setup
Install the pptp server package:
Edit the “/etc/pptpd.conf” configuration file:
Add to it:
Where the “localip” is the address of the server, and the remoteip are the addresses that will be handed out to the clients, it is up to you to adjust these for your network’s requirements.
remoteip 192.168.1.234-238,192.168.1.245
Edit the “/etc/ppp/pptpd-options” configuration file:
Append to the end of the file, the following directives:
Where the IP used for the ms-dns directive is the DNS server for the local network your client will be connecting to and, again, it is your responsibility to adjust this to your network’s configuration.
nobsdcomp
noipx
mtu 1490
mru 1490
Edit the chap secrets file:
Add to it the authentication credentials for a user’s connection, in the following syntax:
Restart the connection’s daemon for the settings to take affect:
If you don’t want to grant yourself access to anything beyond the server, then you’re done on the server side.
Enable Forwarding (optional)
While this step is optional and could be viewed as a security risk for the extremely paranoid, it is my opinion that not doing it defeats the purpose of even having a VPN connection into your network.
By enabling forwarding we make the entire network available to us when we connect and not just the VPN server itself. Doing so allows the connecting client to “jump” through the VPN server, to all other devices on the network.
To achieve this we will be flipping the switch on the “forwarding” parameter of the system.
Edit the “sysctl” file:
Find the “net.ipv4.ip_forward” line and change the parameter from 0 (disabled) to 1 (enabled):
You can either restart the system or issue this command for the setting to take affect:
With forwarding enabled, all the server side settings are prepared.
We recommend using a “Split Tunnel” connection mode for the VPN client.
A more in depth explanation about the recommended “Split Tunnel” mode, as well as instructions for Ubuntu Linux users can be found in the “Setting up a “Split Tunnel” VPN (PPTP) Client on Ubuntu 10.04” guide.
For windows users, follow the guides below to create the VPN client on your system.
PPTP VPN Dialer Setup on XP (split tunnel)
We will create a regular VPN dialer with one note worthy exception, that we will set the system to NOT use it as the “Default Gateway” when connected.
Skipping this step will limit the connecting computer’s surfing speed to the VPN server’s upload speed (usually slow) because all of it’s traffic would be routed through the VPN connection and that’s not what we want.
We need to start the connection wizard, so we will go to control panel.
Go to “Start” and then “Control Panel”.
*If your system is setup with the “Classic Start Menu” you need to just point on the “Control Panel” icon and then select “Network Connections”.
In “Control Panel” double click “Network Connections”.
Double click “New Connection wizard”.
In the “New Connection wizard” welcome screen click “Next”.
Select the “Connect to the network at my workspace” option and then “Next”.
Select the “Virtual Private Network connection” option and then “Next”.
Give a name to the VPN connection.
Type in the name of your VPN servers DNS-name or IP address as seen from the Internet.
Optionally You may choose to “Add a shortcut to the desktop” and “Finish”.
Now comes the tricky part, it is vitally important you do NOT try to connect now and go into the dialer’s “Properties”.
Go to the networking tab and change the “Type of VPN” to “PPTP VPN” as shown in the picture below (this is optional but will shorten the time it takes to connect) then go into “Properties”.
On the next window go into “Advance” without changing anything else.
On the next window, uncheck the “Use default gateway on remote network” option.
Now enter the connection’s credentials as you set them on the server and connect.
That’s it, you should now be able to access all the computers on your network from the XP client… Enjoy.
PPTP VPN Dialer Setup on Win7 (split tunnel)
We will create a regular VPN dialer with one note worthy exception, that we will set the system to NOT use it as the “Default Gateway” when connected.
Skipping this step will limit the connecting computer’s surfing speed to the VPN server’s upload speed (usually slow) because all of it’s traffic would be routed through the VPN connection and that’s not what we want.
We need to start the connection wizard, so we will go to the “Network and Sharing Center”.
Click the network icon in the system tray and then “Open Network and Sharing Center”
In the Network center click on “Set up a new connection or network”.
Select “Connect to a workplace” and then “Next”. Click on the first option of “Use my Internet connection (VPN)”.
Set the address of your VPN server as seen from the internet either by DNS-name or IP.
Even though it won’t connect now because we stil need to go into the dialer’s properties, Set the username and password and hit connect.
After the connection will fails to connect (that’s normal), click on “Set up the connection anyway”.
Back in the “Network Center”, click on “Change adapter settings”.
Find the dialer we have just created, right click it and select “Properties”.
While its optional, for a faster connecting dialer, set the “type” of VPN to PPTP under “the “Security” tab.
Go to the “Networking” tab, select the IPv4 protocol and go into it’s properties.
In the next window, click “Advance” without changing anything else.
On the next window, uncheck the “Use default gateway on remote network” option.
Now enter the connection’s credentials as you set them on the server and connect.
That’s it, you should now be able to access all the computers on your network from the win7 client.
Note: Be sure and read our guide to setting up a VPN client for Ubuntu Linux.
Enjoy :)
