Does OpenVPN work on Ubuntu?

How to configure NAT in OpenVPN?

I am using OpenVPN to set up a VPN for my home network, and I would like to be able to get out on the internet through it. I have been through some tutorials online and still don't have it working.

What I am trying to do is have a single computer on my home network, connected to my VPN router, which will then NAT to the outside world. I also want to be able to connect to this computer from a client on my laptop. This is what I have so far:

My question is - how do I get the NATing from the client to work? I have not been able to find any working guides that actually explain what I need to do, they just point me at the config files and assume that I know what I am doing. I am using a Microsoft Surface RT, if that helps.

I have read that I need to make a port forwarding rule to do this, but I cannot find how to do it in Windows. I tried the port forwarding options in the Windows Firewall (which should do it), but they seem to only work for incoming connections, not outbound.

If anyone could tell me how to do this or point me at a good tutorial that does it, I would really appreciate it. There's a lot of different ways to do this, but you'll want to have some sort of router that's connected to your home network, and another that's connected to your VPN. Then you can just forward ports as needed.

If you're using a router that has a NAT server built-in, then the steps are much simpler. Just make sure you forward the correct ports on the VPN's end, and on the router's NAT end.

It looks like my router (Netgear N300) doesn't have a built-in NAT server, so I would need to buy a new router, as the ones I have will not do this. If I could find a cheap router that had the ports open, and could do NAT, I could probably get it to work. I also think I need a dedicated server (I assume that's what it's called) that I can connect to that is capable of doing this. I have not been able to find one yet.

I have tried all the information that I can find on the internet about this, but none of them work.

Does OpenVPN work on Ubuntu?

I know that OpenVPN does not seem to be easy to install on Ubuntu and that using IPtables was said to work for a lot of people. It does however seems that in 18.04.3 and later it is now easier to setup and configure than the ipfw method I used (thanks to this page - )
Can anyone verify whether OpenVPN does work? Thank you. Short answer, yes OpenVPN works. It is working with the latest Debian based distros like (Xenial, Jessie) Ubuntu 16.04LTS and earlier and (Trusty) Ubuntu 14. It may not work with the newer Ubuntu releases however as they are based on a different kernel version and they use a different network stack for VPN functionality.

For example the following line will fail: sudo ip link add pvc-0 type veth peer name pvcclient mode gre interface vlan 99. source 172.20.10.2 self
If you run the same command on the newer Ubuntu releases the VPN connection will work. As mentioned in the comments OpenVPN can also be installed as a snap package if you prefer that. UPDATE (October 2019). The OpenVPN package doesn't work anymore due to several flaws and inconsistencies between packages and libraries and many security issues. The following blogpost is a good primer to all these issues and should be read before using any VPN software. The blogpost also mentions several projects that are working to fix the problems in OpenVPN and other VPN solutions, which I found interesting reading.

The following is a list of OpenVPN packages available today (as of October 2019): OpenVPN (snap package) - very stable, secure and lightweight. OpenVPN (apt package) - secure and light weight. All these packages are available from the official repository. Long answer (with history). Ubuntu started using systemd in 2023, where the network services are no longer called "inet" and "inet6" anymore but "netlink". The underlying protocols were however kept.

How to configure OpenVPN for Ubuntu?

First of all, my server is a fresh install Ubuntu 18.04 with the latest openssh-server installed from the Ubuntu repositories.

The objective is that when client connect to the server via OpenVPN, their local interface will be used and that their DNS queries will be sent to local resolvers on the server. d, --debug (optional) DEBUG level. v, --verbose (optional) verbosity level. o, --log-output FILE: Specify output log file. P, --plugin PLUGINNAME: OpenVPN plugin to use (-plugin help for a list). p, --plugin-dir directory: Look for plugins in DIR. g, --script STRING or FILE: Use STRING as command and load /bin/true in its stead. If FILE is provided as a path, then use it as script. m, --module MODULENAME: Load Module before OpenVPN executable. M, --module-path PATH: Use PATH as first stage location of load module search list. n, --no-daemon: Run this program non-daemonly. Default: run as process daemon. g, --group GROUPNAME: Group to add users to. w, --work-directory DIR: Working directory for the process. U, --user USERNAME: Use user credentials to access OpenVPN server and client configuration files. h, --help: print help and exit. V, --version: print version and exit. The following options can be given at invocation: C, --no-configuration (OPTIONAL) Do not copy the generated configuration files to the default configuration location. h, --help (OPTIONAL) Display usage information and exit. v, --version (OPTIONAL) Display version information and exit. S, --server TMP: Temporary file used when OpenVPN server runs in detached mode.

Does OpenVPN use NAT?

Is NAT necessary? Will people get confused if they don't have NAT? It's not that clear to me. If I run a VPN server, all the client needs is an IP. So does the NAT affect the IP in any way?
If my server has 2 IPs, one that is connected to the internet (ie my ISP), and another that is NATed by my server itself (so I can share my external IP). Will this create confusion? What is correct? NAT works in an unusual way, it translates the packets into the same format as would be sent to the public IP from the local machine, ie your server, rather than letting it go directly. In order to receive a packet at the local interface you need to understand several things: The IP address of the remote server's network interface. The IP address of your server's interface. How to get a source address for the packet, which may not necessarily be the remote IP address. The protocol type of the packet. There are three ways to set up the VPN: IPsec over IP. IPsec over GRE. IPsec over UDP. Which route you choose depends on where you want to access the tunnel. In order to access the site you need to know: Remote IP address. Remote site name. Protocol name. Tunnel type. To address the question: The NAT would work as follows: NAT translates the incoming packets from server to its local IP address;. Then the router forwards the packet to the remote server over the IPsec VPN. In contrast, IPsec over GRE is similar to normal IP based VPN; however, IPsec over IP creates a transparent tunnel for data. You send packets both ways through IPsec tunnels. The only difference with this type of setup is that the packets originate from your internal IP. So, the packet would originate from your server's internal IP address, which would be your public address, rather than coming directly from your VPN client.