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OpenVPN configuration examples RUT R 00.07 (view source)
Revision as of 14:53, 2 August 2023
, 14:53, 2 August 2023no edit summary
Now we can start configuring OpenVPN Server and Client instances. For this example we will be creating a TUN (Tunnel) type connection that uses the UDP protocol for data transfer and TLS for Authentication. We will be using two RUT routers: '''RUT1''' ('''Server'''; LAN IP: '''192.168.1.1'''; WAN (Public static) IP: '''213.226.191.61''') and '''RUT2''' ('''Client'''; LAN IP: '''192.168.2.1'''); that will be connected into virtual network (with the virtual address: '''10.0.0.0'''):
Now we can start configuring OpenVPN Server and Client instances. For this example we will be creating a TUN (Tunnel) type connection that uses the UDP protocol for data transfer and TLS for Authentication. We will be using two RUT routers: '''RUT1''' ('''Server'''; LAN IP: '''192.168.1.1'''; WAN (Public static) IP: '''213.226.191.61''') and '''RUT2''' ('''Client'''; LAN IP: '''192.168.2.1'''); that will be connected into virtual network (with the virtual address: '''10.0.0.0'''):
[[File:Networking rut configuration openvpn configuration.png|alt=|border|class=tlt-border||1547x1547px]]
[[File:Networking rut configuration openvpn configuration.png|alt=|border|class=tlt-border|1100px]]
To sum up, just make sure the Server and the Clients use the same parameters (same authentication, same port, same protocol, etc.). Another important aspect is the '''Virtual network IP address''' (10.0.0.0 in this case). The Server and the connected Clients will be given IP addresses that belong to this network. If you're creating an exceptionally large network, you might want to change the '''Virtual network netmask'''.
To sum up, just make sure the Server and the Clients use the same parameters (same authentication, same port, same protocol, etc.). Another important aspect is the '''Virtual network IP address''' (10.0.0.0 in this case). The Server and the connected Clients will be given IP addresses that belong to this network. If you're creating an exceptionally large network, you might want to change the '''Virtual network netmask'''.
When you have a Static key, you can start configuring OpenVPN Server and Client instances. For this example we will be creating a TUN (Tunnel) type connection that uses the UDP protocol for data transfer and Static key for Authentication. We will be using two RUT routers: '''RUT1''' ('''Server'''; LAN IP: '''192.168.1.1'''; WAN (Public static) IP: '''213.226.191.61''') and '''RUT2''' ('''Client'''; LAN IP: '''192.168.2.1'''); the two routers will be connected via OpenVPN; the Server's Virtual IP address will be '''10.0.0.1'''; the Client's - '''10.0.0.2''':
When you have a Static key, you can start configuring OpenVPN Server and Client instances. For this example we will be creating a TUN (Tunnel) type connection that uses the UDP protocol for data transfer and Static key for Authentication. We will be using two RUT routers: '''RUT1''' ('''Server'''; LAN IP: '''192.168.1.1'''; WAN (Public static) IP: '''213.226.191.61''') and '''RUT2''' ('''Client'''; LAN IP: '''192.168.2.1'''); the two routers will be connected via OpenVPN; the Server's Virtual IP address will be '''10.0.0.1'''; the Client's - '''10.0.0.2''':
[[File:Networking rut configuration openvpn instances static.png|alt=|border|class=tlt-border||1547x1547px]]
[[File:Networking rut configuration openvpn instances static v1.png|alt=|border|class=tlt-border|1100px]]
To sum up, just make sure the Server and the Clients use the same parameters (same authentication, same port, same protocol, etc.). Other important aspects are the '''Local tunnel endpoint IP''' and the '''Remote tunnel endpoint IP'''. Take note these two particular parameter values are reversed for the individual Client and the Server configurations since these values represent opposite things depending on the instance's perspective.
From the Client side, make sure to enter the correct '''Remote host/IP address''' (213.226.191.61 in this case). This is the Server's Public IP address, not the virtual IP address.
==TAP (bridged) OpenVPN==
This section provides a guide on how to configure a successful OpenVPN TAP (bridged) connection between an OpenVPN Client and Server on RUT routers.
===Configuration===
----
TAP is used for creating a network bridge between Ethernet segments in different locations. For this example we will be creating a TAP (bridged) type connection that uses the UDP protocol for data transfer and TLS for Authentication. We will be using two RUT routers: '''RUT1''' ('''Server'''; LAN IP: '''192.168.1.1'''; WAN (Public static) IP: '''213.226.191.61''') and '''RUT2''' ('''Client'''; LAN IP: '''192.168.1.2'''); the two routers will be connected via OpenVPN.
[[File:Networking rut configuration openvpn tap configuration v1.png|alt=|border|class=tlt-border|1100px]]
To sum up, just make sure the Server and the Clients use the same parameters (same authentication, same port, same protocol, etc.). Since the OpenVPN interface that comes up is bridged with the LAN interface, make sure the routers are in the '''same subnet''' (192.168.1.0 in this case). While making sure of that, don't forget that the routers can't have the same IP address, just the same subnet (for example, if both routers have the LAN IP 192.168.1.1, the connection won't work; if one has, for example, 192.168.1.1 and the other 192.168.1.100, then the connection will work).
For this example, we used TLS Authentication. If you want to use a different Authentication method, refer to the relevant section of this article. The authentication configuration will not be different because of the chosen OpenVPN type (TUN or TAP).
From the Client side, make sure to enter the correct '''Remote host/IP address''' (213.226.191.61 in this case). This is the Server's Public IP address, not the LAN IP address.
==Testing an OpenVPN connection==
The most important thing after configuration is making sure that the newly established connection works. You can check the status of an OpenVPN connection on the '''Status → Network → OpenVPN''' page:
'''Server side'''
[[File:Networking rutxxx configuration openvpn server v1.png|alt=|border|class=tlt-border|1100px]]
'''Client side'''
[[File:Networking rut configuration openvpn client v1.png|alt=|border|class=tlt-border|1100px]]
Another method of testing pinging the other instance's virtual or private IP address. You can send ping packets via CLI, SSH, or from the '''[[RUT955_Administration#Diagnostics|System → Administration → Troubleshoot → Diagnostics]]''' section of the router's WebUI:
[[File:Networking rut configuration diagnostics ping v1.jpg|alt=|border|class=tlt-border]]
Ping the Server's virtual/private IP address from the Client or vice versa. If the ping packets are transmitted successfully, congratulations, your OpenVPN connection is working.
==Additional configuration==
This section will provide examples of some additional OpenVPN-related configurations like how to reach another OpenVPN instance's private LAN or how to use an OpenVPN instance as a Proxy.
===Reaching a device's LAN network===
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You may want your OpenVPN Clients to be able to reach devices that are in the Server device's private network (LAN) or vice versa. This section will provide directions on how to do that.
====Server from Client====
----
To reach another OpenVPN instance's LAN network, you have to have a '''route''' to that network with the '''Virtual remote endpoint''' as the ''' gateway. You can add '''Static routes''' via the command line, but these routes are removed automatically when the router reboots or when the connection goes down even if only for a moment. To solve this, you add permanent static routes via the router's WebUI in the '''[[Routing#Static_Leases|Network → Routing → Static Routes]]''' page. But this method is also not foolproof since it means that if an address ever changes, you would have to also modify the static route on all related devices. '''
----
Another method of reaching the OpenVPN Server's private network from the Client is specifying the network in the OpenVPN Client's configuration. To do so, open the Client's configuration window and fill in these two fields:
[[File:Networking rut configuration openvpn route v1.jpg|alt=|border|class=tlt-border]]
As you can see, the two fields in question are '''Remote network IP address''' and '''Remote network IP netmask'''. The values placed in these fields specify the Server's LAN address and having them filled will automatically add the necessary route into the routing table when the OpenVPN connection goes up. However, if your OpenVPN Server has multiple Clients, you would need to do this for all of them. If that is the case, use this next method.
----
Even another method is pushing the necessary routes via the OpenVPN Server. This method is the most foolproof because it will generate a route to the Server's private network for all connecting Clients. Therefore, in case of configuration changes, you would only have to edit one field in the Server's configuration instead of having to edit all of the Clients' configurations.
To accomplish this, go to OpenVPN Server's configuration window and locate the '''Push option''' field. Let's say that the Server's LAN IP address is 192.168.1.1. In this case use the line '''route 192.168.1.0 255.255.255.0'''
[[File:Networking rutxxx configuration ovpn push settings v1.jpg|alt=|border|class=tlt-border]]
Modify the information so that it reflects your own configuration. Do not specify the gateway, because the command will not work. The correct gateway will be assigned automatically.
====Clients from Server====
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Reaching OpenVPN Clients' private networks from the Server is a bit trickier than the opposite because in order to do so the Server has to be aware of the different specific addresses and Common Names of specific Clients.
To accomplish this, we can use the '''TLS Clients''' function. TLS Clients is a way to more specifically differentiate Clients by their Common Name (CN) found in the client certificate file. It can be used to assign specific VPN addresses to specific Clients and bind them to their LAN addresses so that other devices in the Client‘s LAN can be reached from the Server.
In other words, TLS Clients bind Common Names (found in Client certificates) to Clients' private networks. If the certificate hasn't been tampered with in any after generation, the Common name should be the same as the file name (without the file type extension). For example, a certificate called '''client1.crt''' will likely have the Common Name of '''client1'''. But just to be sure you can open the certificate and check:
[[File:Checking common name.png|alt=|border|class=tlt-border]]
Once you know the Common Names and LAN IP Addresses of your OpenVPN Clients, you can create TLS Clients instances for each of them:
[[File:Networking rut configuration openvpn tls clients v1.jpg|alt=|border|class=tlt-border|1100px]]
In addition, with TLS Clients you can manually assign Virtual local and remote endpoint addresses for the Clients. But these fields are not mandatory and the addresses will be assigned automatically if they are left unchecked.
====Client to Client====
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For Client to Client communication to work you have to do three things:
*Create unique TLS Clients instances for each of the Clients
*Push the necessary routes via the Push option field
*Enable Client to Client functionality in the Server's configuration
=====TLS Clients=====
----
First, configure TLS Clients. You can find the description on how to do that in the section before this one ('''[[OpenVPN configuration examples RUT R 00.07|here]]'''). This is necessary in the case of multiple Clients because the Server will not only be pushing the routes of other Clients but also the routes to the Clients' own networks to their routing tables. This would cause the Clients' routers to be unreachable until the OpenVPN connection is terminated.
TLS Clients solves this issue because the configuration then "tells" the router not to push certain routes to certain Clients. For example, if a router pushes the route '''192.168.5.0 255.255.555.0''' to a Client whose LAN IP address is 192.168.5.1, that Client will not be able to reach its network. TLS Clients prevent this - if a Client, for example, has the LAN IP address of 192.168.5.1, he will not receive the ''route 192.168.5.0 255.255.555.0''.
=====Push options=====
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Next, configure the necessary push options. You will have to include all Clients' networks if you want them all to communicate with each other. For the sake of argument, let's say you have three Clients that belong to three distinct LAN networks:
*192.168.5.0
*192.168.6.0
*192.168.7.0
To give them all the necessary routes, you would have to include these three push options:
route 192.168.5.0 255.255.255.0
route 192.168.6.0 255.255.255.0
route 192.168.7.0 255.255.255.0
The configuration should look something like this:
[[File:Networking rut configuration openvpn push options v1.jpg|alt=|border|class=tlt-border]]
=====Enable Client to Client=====
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The next and final step is to enable the Client to Client functionality. To do this, go to the OpenVPN server's configuration window and put a checkmark at the '''Client to client''' option:
[[File:Networking rut configuration ovpn client to client v1.jpg|alt=|border|class=tlt-border]]
If you did so and followed all of the previous steps in the section, your OpenVPN Clients should now be able to communicate with each other.
===OpenVPN Proxy===
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OpenVPN Servers can be used as Proxies by OpenVPN Clients. This means that the client will be assigned the Public IP address of the OpenVPN server and will be seen as using that IP address when browsing the Internet, transferring data or doing any other online activities. This section provides directions on how to set up an OpenVPN Proxy on RUT routers.
====Push options====
----
The first thing that you have to do is configure Push options in the OpenVPN Server configuration that will change the Clients' default WAN route to OpenVPN and set the DNS server to the OpenVPN Server's LAN IP. To do so open the OpenVPN configuration window and add these options to the Push option field:
'''redirect-gateway def1'''
'''dhcp-option DNS 192.168.1.1'''
In this context, 192.168.1.1 is the OpenVPN Server's LAN IP address. Replace this value with your own Server's LAN IP address.
====Firewall Zone Forwarding====
----
Next, go to the '''Network → Firewall → Zone Forwarding section. Click the '''Edit''' button located next to the '''vpn''' rule and in the subsequent window add a checkmark next to '''wan''' as such:'''
[[File:Networking rut configuration openvpn firewall v1.jpg|alt=|border|class=tlt-border|1100px]]
his will redirect all WAN traffic through the OpenVPN tunnel.
To test this out, on the device behind the OpenVPN Client go to '''http://www.whatsmyip.org/'''. If the website shows the Public IP address of the OpenVPN server, it means the Proxy works.
==Remote configuration==
If you don't have physical or local access in general to the router, there are a few options to configure OpenVPN instances remotely.
===Remote HTTP===
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You can access your router's WebUI from remote locations by enabling the '''Remote HTTP''' option in the '''[[RUT950_Administration#Access_Control|System → Administration → Access Control]]'''. This will only work, however, if you have a Public Static or Public Dynamic IP (not Public Shared; more on IP address types '''[[Private_and_Public_IP_Addresses#Public_IP_address|here]]'''.
You can also enable the SMS Utilities '''web''' rule. More on that '''[[SMS_Utilities#Web_access_Control|here]]'''.
'''Note''': before enabling any type of remote access it is highly recommended that you change the router's default admin password to minimize the risk of malicious remote connections. You can change your password in the '''[[RUT950_Administration#General|System → Administration → General]]''' section.
===Remote Configuration (SMS Utilities)===
----
You can send OpenVPN configurations via '''Remote Configuration''' tool located in the '''Services → SMS Utilities''' section. This method allows you to configure OpenVPN (among other things) just as you would in the OpenVPN section and then send these configurations to another router via SMS. The configuration method is identical to regular OpenVPN configuration. Therefore, additional instructions will not be provided here, but you can find more information on the subject of Remote Configuration '''[[SMS_Utilities#Send_Configuration|here]]'''.
===UCI===
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Yet another method would be using the SMS Utilities '''uci''' rule. You can find information on the rule itself '''[[SMS_Utilities#UCI_API_rule|SMS Utilities manual article]]''' and more detailed information the UCI System in general '''[[UCI_command_usage|here]]'''.
<!--In addition we will provide the basic configurations for OpenVPN Server and Client discussed in this article in "UCI form". This includes OpenVPN TLS, Static key, TUN, TAP configurations for both Server and Client. You can download the text file with these configurations if you follow this link: '''[[Media:ovpn]]'''
'''Note''': remember to change the section and option names and their values according to your own configuration.
'''Note 2''': this method doesn't provide the possibility to send certificates and, therefore, should be used only to edit present OpenVPN instances and not create new ones. -->
==See also==
*[[How to generate TLS certificates (Windows)?]]
*[[OpenVPN client on Windows]]
*[[OpenVPN client on Linux]]
*[[OpenVPN server on Windows]]
*[[OpenVPN traffic split]]
*[[Configuration file .ovpn upload tutorial]]
*Other types of VPNs suported by RUTxxx devices:
**[[IPsec RUTOS configuration example|IPsec configuration examples]]
**[[GRE Tunnel configuration examples RutOS|GRE Tunnel configuration examples]]
**[[PPTP configuration examples RutOS|PPTP configuration examples]]
**[[L2TP configuration examples RutOS|L2TP configuration examples]]
==External links==
https://github.com/OpenVPN/easy-rsa-old - Easy-RSA download
https://winscp.net/eng/download.php - WinSCP download
https://openvpn.net/index.php/open-source/documentation/howto.html - some additional information on OpenVPNs
http://www.whatsmyip.org/
[[Category:VPN]]