What is the difference between use NAT and use routing in OpenVPN?

What is the default subnet for OpenVPN?

Is that what this guide refers to?

Or could you link to a subnet calculator or other explanation on how to set one up, please?

Is it possible to add a local LAN network where OpenVPN server would act as the gateway to this external network, and if so, how to proceed (on which files, services, what to run)? In my situation I would not want to use local LAN but rather connect to the external IP from the local VPN connection. Would it be possible to use different ports for LAN and VPN? Hi, thanks! I tried connecting the OpenVPN client (on a Windows 7 machine) to the example-configuration but all I got was a blank window (no errors, no info). How can I debug the OpenVPN client? The default subnet (2.0/24) is assigned to tun0 (my VPN connection, basically), so what it's not working for you (as opposed to what you think), is assigning those 2.0/24 to a NAT port range. You need to set up a private DNS subnet (10.4)0/24) and assign 10.4)0/24 to your VPN port in order for this to work. Here's how I did it. I think you can do a lot better than mine but hopefully you get the idea. I suggest looking through other forums on that topic (they are always pretty good with help).

I just opened terminal and typed the following: # vpnclient --help 4 Copyright (c) 2023 Christian Hieber. I used these commands: # cat ~/.conf I am running Win 8. I see that it is telling me the default subnet is 2.0/24) Not sure how that works since I don't have 2.0/24 address available at the moment but I will work with what I have. I am using the default configuration provided by the windows installer. Thanks.

You can always have two tun interfaces on the same subnet which is why I said it "should work". One of them will be used for the VPN while the other will be used for your local LAN. Your VPN won't listen on anything else.

Does OpenVPN use NAT?

How do I know that it is not?

I have a home VPN that I use on my LAN. It is an OpenVPN installation with a config file on my NAS running in bridged mode.

Recently I have been having connection problems. I get timeouts and disconnects, then no connection at all. This is usually when I am on mobile devices, so there are no issues on my laptop, just my phones and tablet.

I suspect that this has something to do with the NAT layer. I have tried to ping to the NAS server from the other devices in the house, but nothing. I have tried to access other services on my NAS, and they work fine.

Is this normal for OpenVPN to not work through a NAT configuration? The devices that I am having problems with are on the same network segment as the NAS. I have access to the NAS itself and can browse the internet from it.

I need to find out how to test if this is actually the problem or if there is a problem somewhere else. Here are some things I have checked and think are relevant: I have tried setting up a static IP for the NAS that is not routed (this should be working as long as the devices aren't on the same network as the NAS), and they still have the same issue. I have disabled the Windows Firewall on the NAS and I can still access it. I am using Windows 10 Pro.

I don't have the same issue with any other device. I think this has something to do with routing as the NAS does work fine with its static IP when I connect to it through my router. Re: How do I know that it is not? Thanks for the information. I was able to confirm that it is the NAT layer that is causing the issue. I have tested a couple of apps on the NAS. I have tried using an app that is specifically for NAS use.

It works fine from my phone, but not from my tablet. I have also used a third party application called CloudServer to test an HTTP server on the NAS. This works fine from my phone and tablet. I have only had these problems since I connected to the VPN through my router. Before then, everything was working fine.

I have changed nothing on the NAS.

What is the difference between use NAT and use routing in OpenVPN?

As I stated in the first post, we are setting up a remote site where there is a lot of concern that they will have to pay for "expensive" internet bandwidth.

The connection from our main office will be to the "private" IP address of our remote site -- the Internet will have to get to the Internet (so what I call the "public" IP address will be getting to the public IP address.) How do you set up a remote site in openVPN so that all the sites on their "private" IP network can see the Internet? Do I need to use routing, or should I be able to use NAT? Is there a way to just do one or the other? Thanks for your help.

You would probably want both. It depends on the firewall you're using.

NAT should be fine. The VPN connection will take priority over the internet (unless your proxy is configured to only allow connections via certain protocol). If it's your internal proxy, it should forward everything unmodified. It's possible to have it forward some traffic and not others though. For example, if you've got a server behind your firewall listening on a web port and it just forwards ports 80 (http) through unmodified, then NATing the traffic between clients and that server isn't going to work, but port-forwarding it through your proxy might. You'll probably need to look into iptables/netfilter on your linux box.

Use routing. When the VPN is working and connecting clients to your private network, you don't want them routing their traffic through the internet. You'll have to use iptables or netfilter or something similar on your firewall to redirect the traffic correctly.

How to configure NAT in OpenVPN?

- part 3

As you may know, the OpenVPN's NAT configuration is a bit hard to understand.

For some of us it's a new feature, for others it's old. But we have the perfect tutorial for you!

In the previous articles, we had the most essential topics: configuration file structure for NAT using iptables (how to set up OpenVPN so that your OpenVPN server is available on internet, but don't let other servers ping it). Setting up iptables scripts. What to do with them. Before starting with the real guide, we decided to write one more article because NAT configuration in OpenVPN was really tricky and hard to understand at the beginning, and that's why you need to spend some time looking at it. Just take a look, even if you know all those features from the start, it will be interesting for you.

OpenVPN can be used as a SOCKS5 proxy. The connection goes through OpenVPN and then through SSH. OpenVPN has the ability to create rules to set how data passes through to the client. Let's say we need to send HTTP requests. This tutorial will teach you how to set up your OpenVPN client such that it takes http requests from external servers and routes them through the OpenVPN server.

If we make it harder, you will need to open 2 or 3 ports to the outside. OpenVPN is a multi-layered security system; it will help you with setting up the following: NAT (network address translation). TCP Port Forwarding. ICMP. UDP. So we use multiple methods and we set them up one by one. We should mention that this method depends on the version of OpenVPN which you will use. 2) TCP Port Forwarding. It's almost the same as the first way except it works via the port 4444. You'll have to forward port 4444 on your router and all incoming traffic from that port on the OpenVPN server to your internal network.

The final output. You don't have any connections to the external network, but you have a rule that allows incoming traffic into your VPN network using port 4444.