Difference between revisions of "OpenVPN Access Control"

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<h1>Introduction</h1>
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<p style="color:red">The information on this page is updated in accordance with the [https://wiki.teltonika-networks.com/view/FW_%26_SDK_Downloads'''00.07.06.6'''] firmware version .</p>
  
−
In this example, we will configure an OpenVPN server, will let Client1 and Client2 communicate, while isolating Client3 only to be able to communicate with OpenVPN server
+
=Introduction=
  
−
<h1>Generating certificates for an OpenVPN server</h1>
+
Normally, OpenVPN Client access is controlled by enabling or disabling the Client to Client button in OpenVPN Servers configuration, however, at times, more granular control is required. In this example, we will configure an OpenVPN server with 3 Clients:
  
−
1)Navigate to '''System -> Administration -> Certificates'''
+
<ul>
 +
#<li> Client 1 will be able to communicate with Client 2 and OpenVPN server</li>
 +
#<li> Client 2 will be able to communicate with Client 1 and OpenVPN server</li>
 +
#<li> Client 3 will only be able to communicate with OpenVPN server, but not with any of other clients</li>
 +
</ul>
 +
 
 +
If You have trouble seeing any of the settings, be sure to enable "'''Advanced mode'''"
 +
[[File:Networking rutos manual webui basic advanced mode 75.gif|none|border|center|class=tlt-border]]
 +
=Topology=
 +
 
 +
[[File:OpenVPN Topology v4.png|none|border|left|class=tlt-border|1000x1000px]]
 +
 
 +
 
 +
<ul>
 +
<li> OpenVPN server tunnel address - 10.0.0.1, OpenVPN subnet - 10.0.0.0/27, LAN device address - 192.168.5.114</li>
 +
<li> Client 1 VPN tunnel address - 10.0.0.6, LAN device address - 192.168.10.216</li>
 +
<li> Client 2 VPN tunnel address - 10.0.0.10, LAN device address - 192.168.20.193</li>
 +
<li> Client 3 VPN tunnel address - 10.0.0.14, LAN device address - 192.168.30.178</li>
 +
</ul>
 +
=Generating certificates for an OpenVPN server=
 +
 
 +
Navigate to '''System → Administration → Certificates → Generate Certificate'''
 +
 
 +
Generate 2 certificates. Recommended key size is at least '''2048 bits''' for security reasons:
  
−
2)Generate 2 certificates . Recommended key size is at least 2048 bits for security reasons:
+
&emsp;1. CA
  
−
2.1) CA
+
&emsp;2. Server
  
−
2.2) Server
+
In Certificate Manager download Server certificate.
  
−
3) In Certificate Manager download Server certificate
+
[[File:Certificate download v4.png|none|border|left|class=tlt-border|1100x1100px]]
 +
 
 +
For any OpenVPN clients, You will need to generate “'''Client'''” certificates, download the certificate and key, and send them to the client
  
 
There are multiple methods of how certificates could be generated, you could follow this tutorial instead:
 
There are multiple methods of how certificates could be generated, you could follow this tutorial instead:
 
[[How to generate TLS certificates (Windows)?]]
 
[[How to generate TLS certificates (Windows)?]]
 +
=Creating an OpenVPN server=
  
−
[[File:Certificate download v2.png|none|thumb|alt=|1000x1000px]]
+
Navigate to '''Services -> VPN -> OpenVPN'''. Add a new OpenVPN instance with a '''Server role''' with these settings:
  
−
For any OpenVPN clients, You will need to generate “Client” certificates, download certificate and key, and send them to the client
 
  
−
<h1>Creating an OpenVPN server</h1>
+
[[File:OpenVPN server settings v3.png|none|border|left|class=tlt-border]]
  
−
1) Connect to WebUI and enable Advanced mode
+
1 - <b>Client to client</b> – disabled
  
−
[[File:Networking rutos manual webui basic advanced mode 75.gif|none|thumb|alt=|1000x1000px]]
+
2 - <b>Virtual network IP address</b> – 10.0.0.0
  
−
2) Navigate to '''Services -> VPN -> OpenVPN'''
+
3 - <b>Virtual network netmask</b> – 255.255.255.224
  
−
3) Add a new OpenVPN instance with a Server role
+
4 - <b>Certificate files from device</b> - on
  
−
4) Create an OpenVPN server with these settings
 
  
 +
Press '''"Save & Apply"''', enable OpenVPN server and check if the server is online.
  
−
[[File:OpenVPN server settings v2.png|none|thumb|alt=|1000x1000px]]
+
[[File:OpenVPN server is online v3.png|none|border|left|class=tlt-border|1100x1100px]]
 +
=Connecting clients to the OpenVPN server=
  
−
Virtual network IP address – 10.0.0.0
+
Navigate to '''Services -> VPN -> OpenVPN'''. Add a new OpenVPN instance with a '''Client role''' with these settings:
  
−
Virtual network netmask – 255.255.255.224
+
[[File:OpenVPN Client1 v3.png|none|border|center|class=tlt-border]]
  
−
Client to client – disabled
+
&emsp;&emsp; 1 - '''Remote host/IP address''' - Public IP of the OpenVPN server's router
  
−
Certificate files from device - on
+
&emsp;&emsp; 2 - '''Remote network IP address''' - 10.0.0.0
  
−
5) Press '''"Save & Apply"''', enable OpenVPN server and check if the server is online
+
&emsp;&emsp; 3 - '''Remote network netmask''' - 255.255.255.224
  
−
[[File:OpenVPN server is online v2.png|none|thumb|alt=|1000x1000px]]
+
&emsp;&emsp; 4 - '''Add the certificates from the OpenVPN server''' - Certificate Authority, Client certificate, and Client key which we downloaded in the Certificate Generation step.
  
−
<h1>Connecting clients to the OpenVPN server</h1>
 
  
−
1) Navigate to '''Services -> VPN -> OpenVPN'''
+
Press "'''Save & Apply'''", enable OpenVPN client, and check if the connection is made
  
−
2) Add a new OpenVPN instance with a Client role
+
[[File:OpenVPN Client1 connected v2.png|none|border|left|class=tlt-border|1100x1100px]]
  
−
3) Create an OpenVPN client with these settings
+
Repeat this step for as many clients as You need. For this example, we will have 3 clients.
 +
=Client to Client LAN network communication=
 +
==TLS Clients==
  
−
[[File:OpenVPN Client1 v2.png|none|thumb|alt=|1000x1000px]]
+
On the OpenVPN server router, navigate to '''Services -> VPN -> OpenVPN''', Press "'''Edit'''" on the server, scroll down and add '''TLS clients''' which LAN address You want to have access to, in our case, we add all 3 clients:
 +
===TLS Client 1===
 +
----
 +
[[File:TLS Client1 v3.png|none|border|left|class=tlt-border]]
 +
===TLS Client 2===
 +
----
 +
[[File:TLS Client2 v3.png|none|border|left|class=tlt-border]]
 +
===TLS Client 3===
 +
----
 +
[[File:TLS Client3 v3.png|none|border|left|class=tlt-border]]
  
−
<ul>Remote host/IP address - Public IP of the OpenVPN server's router
+
<ul>
−
<li>Remote network IP address - 10.0.0.0</li>
+
<li>'''Common name''' - common name of the certificate which was generated previously</li>
−
<li>Remote network netmask - 255.255.255.224</li>
+
<li>'''Virtual local endpoint''' - client’s local address in the virtual network</li>
−
<li>And add the certificates from the OpenVPN server - Certificate Authority, Client certificate, and Client key which we downloaded in the Certificate Generation step</li>
+
<li>'''Virtual remote endpoint''' - client’s remote address in the virtual network</li>
 +
<li>'''Private network''' - client's LAN subnet</li>
 +
<li>'''Covered network''' - Which LAN subnet should clients be able to communicate with in the OpenVPN server</li>
 
</ul>
 
</ul>
−
4) Press "Save & Apply", enable OpenVPN client and check if the connection is made
+
==Firewall Zones==
 +
 
 +
This step should be done on OpenVPN '''server and all clients''' that want their LAN subnets be accessible and to access other client's LAN subnets.
 +
 
 +
Navigate to '''Network -> Firewall -> General settings -> Zones''' and set OpenVPN zone to forward traffic to LAN.
 +
 
 +
[[File:OpenVPN to LAN zone forward v2.png|none|border|left|class=tlt-border|1100x1100px]]
 +
==Routes to LAN subnets==
 +
 
 +
Create a route to other client LAN networks using WebUI. This step should be done on '''all clients''' that want their LAN subnets be accessible and to access other client's LAN subnets.
 +
 
 +
 
 +
Navigate to '''Services -> VPN -> OpenVPN''' press '''"Edit"''' on the OpenVPN client and add routes to other client LAN subnets. In this image, we are editing Client 1's configuration's extra options, to add routes to <b>Client 2's (192.168.20.0/24)</b> and <b>Client 3's (192.168.30.0/24)</b> LAN subnets.
 +
 
 +
(In some cases, pushing routes to LAN addresses from the OpenVPN server to clients, breaks routing on the clients, so doing it from the client side is safer, but more time consuming)
 +
 
 +
[[File:OpenVPN client routes v2.png|none|border|left|class=tlt-border]]
 +
=Controlling access with firewall=
 +
 
 +
Navigate to '''Network -> Firewall -> Access Control''' and create a new deny rule. In this example, we are denying Client 3 from accessing any other clients and their LAN networks.
 +
 
 +
[[File:Deny Client3 rule v2.png|none|border|left|class=tlt-border]]
 +
 
 +
 
 +
&emsp;&emsp; 1 - '''Protocol''' - All protocols
 +
 
 +
&emsp;&emsp; 2 - '''Source zone''' - OpenVPN
 +
 
 +
&emsp;&emsp; 3 - '''Source IP''' - OpenVPN remote IP and LAN subnet of client 3
 +
 
 +
&emsp;&emsp; 4 - '''Destination zone''' - OpenVPN
 +
 
 +
&emsp;&emsp; 5 - '''Destination address''' - other client OpenVPN remote endpoints and LAN subnets
  
−
[[File:OpenVPN Client1 connected v2.png|none|thumb|alt=|1000x1000px]]
+
&emsp;&emsp; 6 - '''Action''' - Deny
  
−
5) Repeat this step for as many clients as You need. For this example, we will have 3 clients
 
  
−
<h1>Client to Client LAN network communication</h1>
+
This rule will deny all traffic from Client 3 to other clients, but will not interact with traffic, if it's destination is OpenVPN server or it's LAN subnet.
 +
=Testing the setup=
  
−
1) On the OpenVPN server router, navigate to Services -> VPN -> OpenVPN, Press "Edit" on the server, scroll down and add TLS clients
+
If You have followed the steps correctly, configuration should be finished. These should be the results that You will be getting:
  
−
Add clients which LAN address You want to have access to, in our case, we add all 3 clients
 
  
−
[[File:TLS Client 1.png||none|thumb|alt=|1000x1000px]]
+
Client 1 to Client 2
  
−
<ul>
+
Pinging 192.168.20.193 from 192.168.10.216 with 32 bytes of data:
−
<li>Common name - common name of the certificate which was generated previously</li>
+
Reply from 192.168.20.194: bytes=32 time=172ms TTL=125
−
<li>Virtual local endpoint - client’s local address in the virtual network</li>
+
Reply from 192.168.20.194: bytes=32 time=114ms TTL=125
−
<li>Virtual remote endpoint - client’s remote address in the virtual network</li>
+
Reply from 192.168.20.194: bytes=32 time=113ms TTL=125
−
<li>Private network - client's LAN subnet</li>
+
Reply from 192.168.20.194: bytes=32 time=294ms TTL=125
−
<li>Covered network - Which LAN subnet should clients be able to communicate with in the OpenVPN server</li>
+
 
−
</ul>
+
Client 1 to Client 3
 +
 
 +
Pinging 192.168.30.178 from 192.168.10.216 with 32 bytes of data:
 +
Request timed out.
 +
Request timed out.
 +
Request timed out.
 +
Request timed out.
  
−
This step should be done on OpenVPN server and all clients that want their LAN subnets be accessible and to access other client's LAN subnets
+
Client 2 to Client 1
  
−
1) Navigate to '''Network -> Firewall -> General settings -> Zones''' and set OpenVPN zone to forward traffic to LAN
+
Pinging 192.168.10.216 from 192.168.20.193 with 32 bytes of data:
 +
Reply from 192.168.10.216: bytes=32 time=185ms TTL=125
 +
Reply from 192.168.10.216: bytes=32 time=123ms TTL=125
 +
Reply from 192.168.10.216: bytes=32 time=227ms TTL=125
 +
Reply from 192.168.10.216: bytes=32 time=189ms TTL=125
  
−
[[File:OpenVPN to LAN zone forward.png|none|thumb|alt=|1000x1000px]]
+
Client 2 to Client 3
  
 +
Pinging 192.168.30.178 from 192.168.20.193 with 32 bytes of data:
 +
Request timed out.
 +
Request timed out.
 +
Request timed out.
 +
Request timed out.
  
−
This step should be done on all <b>clients</b> that want their LAN subnets be accessible and to access other client's LAN subnets
+
Client 3 to Client 1
  
 +
Pinging 192.168.10.216 from 192.168.30.178 with 32 bytes of data:
 +
Request timed out.
 +
Request timed out.
 +
Request timed out.
 +
Request timed out.
  
−
1) Create a route to other client LAN networks using WebUI or CLI. To create route from client 1's LAN to client 2's LAN using CLI use this command
+
Client 3 to Client 2
  
−
  ip route add 192.168.20.0/24 via 10.0.0.6
+
  Pinging 192.168.20.193 from 192.168.30.178 with 32 bytes of data:
 +
Request timed out.
 +
Request timed out.
 +
Request timed out.
 +
Request timed out.
  
−
<h1>Controlling access with firewall</h1>
+
And server can reach all of the clients and their LAN subnets
  
−
1) Navigate to Network -> Firewall -> Access Control
+
Pinging 192.168.10.216 from 192.168.5.114 with 32 bytes of data:
 +
Reply from 192.168.5.114: bytes=32 time=264ms TTL=62
 +
Reply from 192.168.5.114: bytes=32 time=138ms TTL=62
 +
Reply from 192.168.5.114: bytes=32 time=81ms TTL=62
 +
Reply from 192.168.5.114: bytes=32 time=107ms TTL=62
 +
 +
Pinging 192.168.20.193 from 192.168.5.114 with 32 bytes of data:
 +
Reply from 192.168.5.114: bytes=32 time=61ms TTL=62
 +
Reply from 192.168.5.114: bytes=32 time=376ms TTL=62
 +
Reply from 192.168.5.114: bytes=32 time=132ms TTL=62
 +
Reply from 192.168.5.114: bytes=32 time=232ms TTL=62
 +
 +
Pinging 192.168.30.178 from 192.168.5.114 with 32 bytes of data:
 +
Reply from 192.168.5.114: bytes=32 time=226ms TTL=62
 +
Reply from 192.168.5.114: bytes=32 time=327ms TTL=62
 +
Reply from 192.168.5.114: bytes=32 time=111ms TTL=62
 +
Reply from 192.168.5.114: bytes=32 time=80ms TTL=62
  
−
2) Create a new deny rule. In this example, we are denying Client 3 from accessing any other clients and their LAN networks
+
<br>
  
−
[[File:Deny Client3 rule.png|none|thumb|alt=|1000x1000px]]
+
=See also=
  
 
<ul>
 
<ul>
−
<li>Source interface - OpenVPN</li>
+
<li>[[OpenVPN_configuration_examples_RUT_R_00.07]]</li>
−
<li>Destination interface - OpenVPN</li>
+
<li>[[How to generate TLS certificates (Windows)?]]</li>
−
<li>Source IP - OpenVPN remote IP and LAN subnet of client 3</li>
+
<li>[[OpenVPN client on Windows]]</li>
−
<li>Destination IP - other client OpenVPN remote endpoints and LAN subnets</li>
+
<li>[[OpenVPN client on Linux]]</li>
−
<li>Action - Deny</li>
+
<li>[[OpenVPN server on Windows]]</li>
 +
<li>[[OpenVPN traffic split]]</li>
 +
<li>[[Configuration file .ovpn upload tutorial]]</li>
 +
<li>[[Firewall traffic rules]]</li>
 
</ul>
 
</ul>
−
This rule will deny all traffic from Client 3 to other clients, but will not interact with traffic, if it's destination is OpenVPN server or it's LAN subnet
 
  
−
<h1>See also</h1>
+
 
−
<ul>
+
=External links=
−
<li>[[OpenVPN_configuration_examples_RUT_R_00.07|OpenVPN configuration examples]]</li>
+
 
−
</ul>
+
https://openvpn.net/index.php/open-source/documentation/howto.html - some additional information on OpenVPN

Latest revision as of 14:55, 9 April 2024

The information on this page is updated in accordance with the 00.07.06.6 firmware version .

Introduction

Normally, OpenVPN Client access is controlled by enabling or disabling the Client to Client button in OpenVPN Servers configuration, however, at times, more granular control is required. In this example, we will configure an OpenVPN server with 3 Clients:

    2. Client 1 will be able to communicate with Client 2 and OpenVPN server
    4. Client 2 will be able to communicate with Client 1 and OpenVPN server
    6. Client 3 will only be able to communicate with OpenVPN server, but not with any of other clients

If You have trouble seeing any of the settings, be sure to enable "Advanced mode"

Networking rutos manual webui basic advanced mode 75.gif

Topology

OpenVPN Topology v4.png


  • OpenVPN server tunnel address - 10.0.0.1, OpenVPN subnet - 10.0.0.0/27, LAN device address - 192.168.5.114
  • Client 1 VPN tunnel address - 10.0.0.6, LAN device address - 192.168.10.216
  • Client 2 VPN tunnel address - 10.0.0.10, LAN device address - 192.168.20.193
  • Client 3 VPN tunnel address - 10.0.0.14, LAN device address - 192.168.30.178

Generating certificates for an OpenVPN server

Navigate to System → Administration → Certificates → Generate Certificate

Generate 2 certificates. Recommended key size is at least 2048 bits for security reasons:

 1. CA

 2. Server

In Certificate Manager download Server certificate.

Certificate download v4.png

For any OpenVPN clients, You will need to generate “Client” certificates, download the certificate and key, and send them to the client

There are multiple methods of how certificates could be generated, you could follow this tutorial instead: How to generate TLS certificates (Windows)?

Creating an OpenVPN server

Navigate to Services -> VPN -> OpenVPN. Add a new OpenVPN instance with a Server role with these settings:


OpenVPN server settings v3.png

1 - Client to client – disabled

2 - Virtual network IP address – 10.0.0.0

3 - Virtual network netmask – 255.255.255.224

4 - Certificate files from device - on


Press "Save & Apply", enable OpenVPN server and check if the server is online.

OpenVPN server is online v3.png

Connecting clients to the OpenVPN server

Navigate to Services -> VPN -> OpenVPN. Add a new OpenVPN instance with a Client role with these settings:

OpenVPN Client1 v3.png

   1 - Remote host/IP address - Public IP of the OpenVPN server's router

   2 - Remote network IP address - 10.0.0.0

   3 - Remote network netmask - 255.255.255.224

   4 - Add the certificates from the OpenVPN server - Certificate Authority, Client certificate, and Client key which we downloaded in the Certificate Generation step.


Press "Save & Apply", enable OpenVPN client, and check if the connection is made

OpenVPN Client1 connected v2.png

Repeat this step for as many clients as You need. For this example, we will have 3 clients.

Client to Client LAN network communication

TLS Clients

On the OpenVPN server router, navigate to Services -> VPN -> OpenVPN, Press "Edit" on the server, scroll down and add TLS clients which LAN address You want to have access to, in our case, we add all 3 clients:

TLS Client 1

TLS Client1 v3.png

TLS Client 2

TLS Client2 v3.png

TLS Client 3

TLS Client3 v3.png
  • Common name - common name of the certificate which was generated previously
  • Virtual local endpoint - client’s local address in the virtual network
  • Virtual remote endpoint - client’s remote address in the virtual network
  • Private network - client's LAN subnet
  • Covered network - Which LAN subnet should clients be able to communicate with in the OpenVPN server

Firewall Zones

This step should be done on OpenVPN server and all clients that want their LAN subnets be accessible and to access other client's LAN subnets.

Navigate to Network -> Firewall -> General settings -> Zones and set OpenVPN zone to forward traffic to LAN.

OpenVPN to LAN zone forward v2.png

Routes to LAN subnets

Create a route to other client LAN networks using WebUI. This step should be done on all clients that want their LAN subnets be accessible and to access other client's LAN subnets.


Navigate to Services -> VPN -> OpenVPN press "Edit" on the OpenVPN client and add routes to other client LAN subnets. In this image, we are editing Client 1's configuration's extra options, to add routes to Client 2's (192.168.20.0/24) and Client 3's (192.168.30.0/24) LAN subnets.

(In some cases, pushing routes to LAN addresses from the OpenVPN server to clients, breaks routing on the clients, so doing it from the client side is safer, but more time consuming)

OpenVPN client routes v2.png

Controlling access with firewall

Navigate to Network -> Firewall -> Access Control and create a new deny rule. In this example, we are denying Client 3 from accessing any other clients and their LAN networks.

Deny Client3 rule v2.png


   1 - Protocol - All protocols

   2 - Source zone - OpenVPN

   3 - Source IP - OpenVPN remote IP and LAN subnet of client 3

   4 - Destination zone - OpenVPN

   5 - Destination address - other client OpenVPN remote endpoints and LAN subnets

   6 - Action - Deny


This rule will deny all traffic from Client 3 to other clients, but will not interact with traffic, if it's destination is OpenVPN server or it's LAN subnet.

Testing the setup

If You have followed the steps correctly, configuration should be finished. These should be the results that You will be getting:


Client 1 to Client 2 

Pinging 192.168.20.193 from 192.168.10.216 with 32 bytes of data:
Reply from 192.168.20.194: bytes=32 time=172ms TTL=125
Reply from 192.168.20.194: bytes=32 time=114ms TTL=125
Reply from 192.168.20.194: bytes=32 time=113ms TTL=125
Reply from 192.168.20.194: bytes=32 time=294ms TTL=125

Client 1 to Client 3 

Pinging 192.168.30.178 from 192.168.10.216 with 32 bytes of data:
Request timed out.
Request timed out.
Request timed out.
Request timed out.

Client 2 to Client 1 

Pinging 192.168.10.216 from 192.168.20.193 with 32 bytes of data:
Reply from 192.168.10.216: bytes=32 time=185ms TTL=125
Reply from 192.168.10.216: bytes=32 time=123ms TTL=125
Reply from 192.168.10.216: bytes=32 time=227ms TTL=125
Reply from 192.168.10.216: bytes=32 time=189ms TTL=125

Client 2 to Client 3 

Pinging 192.168.30.178 from 192.168.20.193 with 32 bytes of data:
Request timed out.
Request timed out.
Request timed out.
Request timed out.

Client 3 to Client 1 

Pinging 192.168.10.216 from 192.168.30.178 with 32 bytes of data:
Request timed out.
Request timed out.
Request timed out.
Request timed out.

Client 3 to Client 2 

Pinging 192.168.20.193 from 192.168.30.178 with 32 bytes of data:
Request timed out.
Request timed out.
Request timed out.
Request timed out.

And server can reach all of the clients and their LAN subnets 

Pinging 192.168.10.216 from 192.168.5.114 with 32 bytes of data:
Reply from 192.168.5.114: bytes=32 time=264ms TTL=62
Reply from 192.168.5.114: bytes=32 time=138ms TTL=62
Reply from 192.168.5.114: bytes=32 time=81ms TTL=62
Reply from 192.168.5.114: bytes=32 time=107ms TTL=62

Pinging 192.168.20.193 from 192.168.5.114 with 32 bytes of data:
Reply from 192.168.5.114: bytes=32 time=61ms TTL=62
Reply from 192.168.5.114: bytes=32 time=376ms TTL=62
Reply from 192.168.5.114: bytes=32 time=132ms TTL=62
Reply from 192.168.5.114: bytes=32 time=232ms TTL=62

Pinging 192.168.30.178 from 192.168.5.114 with 32 bytes of data:
Reply from 192.168.5.114: bytes=32 time=226ms TTL=62
Reply from 192.168.5.114: bytes=32 time=327ms TTL=62
Reply from 192.168.5.114: bytes=32 time=111ms TTL=62
Reply from 192.168.5.114: bytes=32 time=80ms TTL=62


See also


External links

https://openvpn.net/index.php/open-source/documentation/howto.html - some additional information on OpenVPN

Retrieved from "https://wiki.teltonika-networks.com/index.php?title=OpenVPN_Access_Control&oldid=123341"