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    How to prevent OpenVPN clients from accessing local IP addresses?

    Scheduled Pinned Locked Moved OpenVPN
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    • P
      pfguy2018
      last edited by pfguy2018

      No, a completely different subnet. (LAN is 192.168.x.x, OpenVPN clients are assigned 10.0.x.x, DNS server would be 192.168.x.1 (edit - DNS could also be reachable at 10.0.x.1))

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      • NogBadTheBadN
        NogBadTheBad
        last edited by

        Here's what I do with IPSec:-

        0_1533298791453_Untitled.jpeg

        I hand out specific IP addresses to various users via FreeRadius.

        n_ipsec_trusted = 172.16.8.0/25

        n_ipsec_non_trusted = 172.16.8.128/25

        Andy

        1 x Netgate SG-4860 - 3 x Linksys LGS308P - 1 x Aruba InstantOn AP22

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        • P
          pfguy2018
          last edited by

          I already have similar rules on the OpenVPN rules tab, but the rules do not seem to block as intended, and local access is still happening. Here is what I have:

          0_1533300846540_Screen Shot 2018-08-03 at 8.52.59 AM.png

          ("Local" alias is all my local subnets other than the OpenVPN subnet)

          Any suggestions?

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          • NogBadTheBadN
            NogBadTheBad
            last edited by NogBadTheBad

            Whats the Advanced filter rule at the bottom doing ?

            Also why the gateway, do you have a multi wan set-up?

            Andy

            1 x Netgate SG-4860 - 3 x Linksys LGS308P - 1 x Aruba InstantOn AP22

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            • P
              pfguy2018
              last edited by

              The only advanced option is the gateway - WAN_DHCP. I am not using a multiwan setup, but there are several outgoing OpenVPN clients. I think I stuck the gateway in there to make sure the connection went out over the WAN connection rather than the OpenVPN client connections. Is that somehow causing the issue?

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              • NogBadTheBadN
                NogBadTheBad @pfguy2018
                last edited by

                @pfguy2018

                Not sure but there is no need if you have a single wan connection.

                try enabling logging on your rules and see what rule is being hit.

                Andy

                1 x Netgate SG-4860 - 3 x Linksys LGS308P - 1 x Aruba InstantOn AP22

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                • P
                  pfguy2018
                  last edited by

                  Turns out my rules work, for the most part. I was testing the connection by connecting to the VPN through my home network. When I connected outside my home lan, the rules worked as intended - DNS provided by the pfSense box, no other connections with the local subnets permitted. I am not sure why the connections were permitted when I originated from the home lan, but this is of little concern, as I would not normally be using a VPN when I am already on the network to which I am trying to connect.

                  NogBadTheBadN DerelictD 2 Replies Last reply Reply Quote 0
                  • NogBadTheBadN
                    NogBadTheBad @pfguy2018
                    last edited by

                    @pfguy2018 said in How to prevent OpenVPN clients from accessing local IP addresses?:

                    Turns out my rules work, for the most part. I was testing the connection by connecting to the VPN through my home network. When I connected outside my home lan, the rules worked as intended - DNS provided by the pfSense box, no other connections with the local subnets permitted. I am not sure why the connections were permitted when I originated from the home lan, but this is of little concern, as I would not normally be using a VPN when I am already on the network to which I am trying to connect.

                    By the sound of things you've set it up as a split tunnel.

                    Andy

                    1 x Netgate SG-4860 - 3 x Linksys LGS308P - 1 x Aruba InstantOn AP22

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                    • DerelictD
                      Derelict LAYER 8 Netgate @pfguy2018
                      last edited by

                      I am not sure why the connections were permitted when I originated from the home lan

                      @pfguy2018 Because the local LAN was a local subnet to the host. That traffic won't go out the VPN, but straight out the interface.

                      Chattanooga, Tennessee, USA
                      A comprehensive network diagram is worth 10,000 words and 15 conference calls.
                      DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
                      Do Not Chat For Help! NO_WAN_EGRESS(TM)

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                      • P
                        pfguy2018
                        last edited by

                        I get that. But the client was also able to access vlans on different subnetd when connected to the VPN server while originating from a home vlan. That is what confused me. (As noted earlier, this does not occur if connecting to the VPN server from outside the home)

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