Tun0 Interface Not Present in ifconfig After OpenVPN Configuration

Hello Toradex Community,
I am using imx6ull Aster Carrier Board with TDX Wayland with XWayland Upstream 6.7.0-devel-20240710125113+build.0 (kirkstone) Colibri-iMX6ULL-eMMC_Reference-Multimedia-Image-upstream tdx-reference-multimedia-image (OS)

I’m facing an issue with OpenVPN on my i.MX6ULL board. After configuring OpenVPN, I notice that the tun0 interface is not appearing when I run ifconfig. tun kernel module is already loaded and service file of openvpn client is also active.

Here is the reference link

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It seems like you’ve already taken some important steps, such as ensuring the tun kernel module is loaded and the OpenVPN client service is active. However, the absence of the tun0 interface in ifconfig suggests that there might be an issue with the OpenVPN configuration or the service startup.

Here are a few steps you can take to troubleshoot and resolve the issue:

  1. Check OpenVPN Logs:

    • The OpenVPN logs can provide detailed information about what might be going wrong. You can check the logs using:
      sudo journalctl -u openvpn@client
      
    • Look for any error messages or warnings that might indicate why the tun0 interface is not being created.
  2. Verify Configuration Files:

    • Ensure that the client.conf file is correctly configured. Pay special attention to the following lines:
      dev tun
      ca /etc/openvpn/ca.crt
      cert /etc/openvpn/client.crt
      key /etc/openvpn/client.key
      remote <server_ip> <port>
      
    • Make sure the paths to the certificate and key files are correct and that the remote line points to the correct server IP and port.
  3. Check Network Configuration:

    • Ensure that IP forwarding is enabled on your system. You can check this by running:
      sudo sysctl net.ipv4.ip_forward
      
    • If it is not enabled, you can enable it by adding the following line to /etc/sysctl.conf:
      net.ipv4.ip_forward = 1
      
    • Then reload the sysctl configuration:
      sudo sysctl -p
      
  4. Restart OpenVPN Service:

    • Sometimes, simply restarting the OpenVPN service can resolve the issue:
      sudo systemctl restart openvpn@client
      
  5. Check for Conflicting Network Interfaces:

    • Ensure that there are no other network interfaces that might be conflicting with tun0.
  6. Manual Interface Creation:

    • As a last resort, you can try to manually create the tun0 interface to see if it helps:
      sudo ip tuntap add dev tun0 mode tun
      sudo ip link set tun0 up
      

If none of these steps resolve the issue, please provide more details from the OpenVPN logs, and any error messages you encounter. This will help in diagnosing the problem further.

Please, also check if these links can help you solve your problem:

Can't open PID file /run/openvpn/client.pid (yet?) after start: Operation not permitted in VPN client configuration in imx6ull.

I tried these still same issue.

root@colibri-imx6ull-emmc-07324251:~# systemctl status openvpn@client
● openvpn@client.service - OpenVPN Robust And Highly Flexible Tunneling Application On client
     Loaded: loaded (/lib/systemd/system/openvpn@.service; enabled; vendor preset: disabled)
     Active: active (running) since Fri 2024-09-06 10:56:54 UTC; 55s ago
    Process: 621 ExecStart=/usr/sbin/openvpn --daemon --writepid /var/run/openvpn/client.pid --cd /etc/openvpn/ --cipher AES-256-GCM --data-ciphers AES-256-GCM:AES-128-GCM:AES-256-CBC:AES-128-CBC:BF-CBC>
   Main PID: 626 (openvpn)
     CGroup: /system.slice/system-openvpn.slice/openvpn@client.service
             └─ 626 /usr/sbin/openvpn --daemon --writepid /var/run/openvpn/client.pid --cd /etc/openvpn/ --cipher AES-256-GCM --data-ciphers AES-256-GCM:AES-128-GCM:AES-256-CBC:AES-128-CBC:BF-CBC --conf>

Sep 06 10:56:53 colibri-imx6ull-emmc-07324251 systemd[1]: Starting OpenVPN Robust And Highly Flexible Tunneling Application On client...
Sep 06 10:56:54 colibri-imx6ull-emmc-07324251 systemd[1]: Started OpenVPN Robust And Highly Flexible Tunneling Application On client.
root@colibri-imx6ull-emmc-07324251:~# ifconfig
eth0: flags=-28605<UP,BROADCAST,RUNNING,MULTICAST,DYNAMIC>  mtu 1500
        inet 192.168.0.152  netmask 255.255.255.0  broadcast 192.168.0.255
        inet6 fe80::214:2dff:fe6f:c25b  prefixlen 64  scopeid 0x20<link>
        ether 00:14:2d:6f:c2:5b  txqueuelen 1000  (Ethernet)
        RX packets 307  bytes 32220 (31.4 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 142  bytes 18774 (18.3 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1000  (Local Loopback)
        RX packets 97  bytes 8457 (8.2 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 97  bytes 8457 (8.2 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

usb0: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
        ether be:b3:b4:6e:8d:27  txqueuelen 1000  (Ethernet)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

Hello…

As per me… I also faced the same issue. Thanks for the solution. I will diffidently tried this.

Thanks!

@ToradexAI
Will I get a response?