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    OpenVPN: connection established but cannot access LAN or WebGUI

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    • F
      Flintstone_404
      last edited by

      Dear all,

      maybe I am making a silly mistake or just overlooked something, but I cannot make OpenVPN work as I would like it to. I have a static IPv4 address and my internal network is 10.10.0.1/16. Following my OpenVPN setup network setup:

      • Subnet for OpenVPN:
        10.10.2.1/24 --> can establish VPN connection, but cannot access webGUI or any other LAN connected device
        10.10.2.1/16 --> cannot establish VPN connection
        10.10.0.1/16 --> cannot establish VPN connection
      • Networks to access with VPN: 10.10.0.1/16 --> not possible even if VPN is connected.

      I do not know what I am doing wrong, but it seems already weird to me that I cannot connect a device via VPN to the "main" subnet 10.10.0.1/16. Despite the fact that there is a different interface connecting (WAN vs OpenVPN), I do not see a reason why that should not work. Furthermore, the non-connectivity to the main subnet is completely unclear to me.
      I would really appreciate if someone could help me out of my VPN-misery.

      Cheers and thanks in advance!

      V 1 Reply Last reply Reply Quote 0
      • V
        viragomann @Flintstone_404
        last edited by viragomann

        @flintstone_404 said in OpenVPN: connection established but cannot access LAN or WebGUI:

        Subnet for OpenVPN:
        10.10.2.1/24 --> can establish VPN connection, but cannot access webGUI or any other LAN connected device
        10.10.2.1/16 --> cannot establish VPN connection
        10.10.0.1/16 --> cannot establish VPN connection
        Networks to access with VPN: 10.10.0.1/16 --> not possible even if VPN is connected.

        None of these is a network address!
        You have to state a network address for the tunnel network like 10.25.25.0/24. As well you have to state a network for "local netwoks", e.g. 10.10.0.0/16.

        AND ensure that the tunnel and local network are not overlapping!

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        • F
          Flintstone_404 @viragomann
          last edited by

          @viragomann Thanks for the reply.
          So that I get it correct: the network of my LAN and the OpenVPN should be non-overlapping. Following your example this would mean: given that my LAN network is 10.10.0.0/16, the OpenVPN network could be 10.11.0.0/16 (so they are not overlapping).
          To allow the OpenVPN network to have access to my LAN network, 10.10.0.0/16 has to be put in the field which asks for the networks to communicate with?

          None of these is a network address! In my understanding 10.10.2.1/24 would be a valid address encompassing the range 10.10.2.1 - 10.10.2.254 and broadcasting using 10.10.2.255. Given the fact that LAN and OpenVPN should not be overlapping, I do understand that this choice is not usable. Can you explain why I could nonetheless establish a OpenVPN connection using 10.10.2.1/24 as OpenVPN network?

          Have a nice sunday and many thanks for your input!

          V 1 Reply Last reply Reply Quote 0
          • V
            viragomann @Flintstone_404
            last edited by

            @flintstone_404 said in OpenVPN: connection established but cannot access LAN or WebGUI:

            So that I get it correct: the network of my LAN and the OpenVPN should be non-overlapping.

            Correct. If the OpenVPN tunnel network is overlapping with LAN routing is not possible.

            Following your example this would mean: given that my LAN network is 10.10.0.0/16, the OpenVPN network could be 10.11.0.0/16 (so they are not overlapping).

            Would be ok. But any good reason to have a /16 VPN tunnel? Do you intend to have 65k clients?

            In my understanding 10.10.2.1/24 would be a valid address encompassing the range 10.10.2.1 - 10.10.2.254 and broadcasting using 10.10.2.255.

            It's a valid IP address, but not a network address. You need to state a network address for the tunnel network.
            But also not 10.10.2.0/24 since this is part of your 10.10.0.0/16 LAN.

            F 1 Reply Last reply Reply Quote 1
            • F
              Flintstone_404 @viragomann
              last edited by Flintstone_404

              @viragomann It is all working now! Thank you!

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