CentOS: How to set up a VPN server (PPTP) Part.3
How to set up a VPN server (PPTP) with CentOS
Open the door on the firewall
Now that the service is operational, we must ensure that it is reachable!
First, we open the port on the firewall: Follow System -> Administration -> Security Level and Firewall to launch the configuration panel.
Click the Add button at the bottom right, enter 1723, press Ok and confirmed repeatedly until you close the tool.
Configure the router
If the server’s Internet connection to use a router, you must also configure the same port forwarding (port forwarding) to the VPN server (for local trace the IP address, refer to the article “Configure IP address and DNS on CentOS“.
The exact procedure varies from model to model. As for the ubiquitous Alice Gate provided on loan by Telecom Italy, For all other devices, you should refer to the instruction booklet.
This step alone, however, may not be enough. Some routers block because the protocol Generic Routing Encapsulation (GRE) used in this scenario: it is therefore necessary to browse through the available options and make sure that this barrier is not active.
To complicate matters further, other devices provide an option called VPN Passthrough (PPTP Passthrough, or) that must be explicitly activated in turn to achieve the goal: again, you are called to use a little ‘technical acumen and the slog’ management interface of the device to achieve the goal.
Getting a dynamic domain name
In order to reach the CentOS server from the outside, is particularly convenient to use a dynamic domain name (it will be something like servervpn.no-ip.org): NO-IP is definitely a great tool as well as DynDNS.
I strongly suggest you to associate one to your server before going any further.
Connect from client
At this point, everything should be ready. You just have to connect from a client! The procedure was shown in “How to connect to a VPN server with Windows 7 and Ubuntu”
Once the connection is established, the CentOS server takes care to join in an (almost) clear the two branches of the network: that of the VPN and local network segment which provides access.
Note that the remote Windows PC on the LAN may not be correctly displayed under My Network: if so, use the usual \ \ PC-name from Windows Explorer to reach them directly.
See also:
1. How to set up a VPN server (PPTP) Part.1
2. How to set up a VPN server (PPTP) Part.2