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    Local traffic on a VLAN with a remote gateway

    Scheduled Pinned Locked Moved IPsec
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    • F
      FauxShow
      last edited by

      Let's say I have two VLANs on router A; 10.0.1/24 and 10.0.2/24. The second VLAN has a site-to-site VPN with 0.0.0.0/0 as the right side; a remote gateway. All traffic from hosts on the 10.0.2/24 network goes over the VPN and NATs out from router B. However, from a computer on 10.0.1/24 I want to reach a server on a 10.0.2.x address for management/updates. Is there some sort of split tunnelling, tunnel network exception or even a order of operations change that can allow the two local networks to reach each other again?

      brb; gotta reboot my pfsense

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      • johnpozJ
        johnpoz LAYER 8 Global Moderator
        last edited by

        So these are vpn clients on pfsense?

        So you have the attached?  You have a client in this 10.0.2/24 network that points to a different gateway than pfsense.. Or your doing policy routing on pfsense?  If so I am confused about where the vpn comes in?

        If your setup is like 1st then you would need host route on the box in 10.0.2 network to tell it to get to 10.0.1 talk to the IP of pfsense on the 10.0.2 network.

        If your setup is like 2nd drawing with policy routing, it should work just fine if 10.0.1 is creating the connection.  If box on 10.0.2 is wanting to talk to 10.0.1 and he starts the conversation then you would need rules above where you policy route it out the vpn connection.

        I always say a picture is worth a 1000's words - so simple drawing of your network would go a long way in helping you solve your problem.

        2networks.png
        2networks.png_thumb
        policyroute.png
        policyroute.png_thumb

        An intelligent man is sometimes forced to be drunk to spend time with his fools
        If you get confused: Listen to the Music Play
        Please don't Chat/PM me for help, unless mod related
        SG-4860 24.11 | Lab VMs 2.8, 24.11

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        • F
          FauxShow
          last edited by

          Definitely like the second drawing. pfSense on both sides. I sent an email with a few more specifics.

          I don't believe this is how pfSense should behave, but I don't have any spare Cisco gear to replicate my setup using a different router.

          If you want to test, however, I could lend a cloud instance.

          brb; gotta reboot my pfsense

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          • johnpozJ
            johnpoz LAYER 8 Global Moderator
            last edited by

            If your setup is like drawing 2 - out of the box you would be able to access stuff on 10.0.2 from 10.0.1.. Other than local firewalls on the devices in question.

            Policy routing devices on 10.0.2 to a gateway has nothing to do with connections from 10.0.1.. Now if you do not allow access in the rules on 10.0.2 to 10.0.1 then 10.0.2 clients would not be able to create connections to 10.0.1 - but they for sure could answer to 10.0.1

            Your not changing the gateway on the 10.0.2 client, or running a vpn client on that device directly are you?  You sure do not need to nat these clients to your vpn IP, as long as the other end allows and understands how to get back to this network via the vpn, etc.

            Please show your outbound nat rules and your policy routing, ie your rules on your 10.0.2 interface.

            An intelligent man is sometimes forced to be drunk to spend time with his fools
            If you get confused: Listen to the Music Play
            Please don't Chat/PM me for help, unless mod related
            SG-4860 24.11 | Lab VMs 2.8, 24.11

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            • F
              FauxShow
              last edited by

              For the sake of testing, both interfaces have rules that allow their subnet anywhere. If I disable the VPN then the hosts can reach other, but as soon as the VPN is enabled that stops.

              brb; gotta reboot my pfsense

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              • F
                FauxShow
                last edited by

                It's worth noting that I've done remote gateways a few times on a few different pfSense instances with the same behavior over the past few years. I've made workarounds by creating an IP alias on the network with the remote gateway and added secondary IPs on the servers on that VLAN, with routes applied that backchannel the local networks. It's messy and impossible to do with iPhones and other devices I'm using now.

                brb; gotta reboot my pfsense

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                • DerelictD
                  Derelict LAYER 8 Netgate
                  last edited by

                  If you are policy routing to the VPN you have to bypass said policy routing for local subnets:

                  https://doc.pfsense.org/index.php/Bypassing_Policy_Routing

                  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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                  • johnpozJ
                    johnpoz LAYER 8 Global Moderator
                    last edited by

                    "I've made workarounds by creating an IP alias on the network with the remote gateway and added secondary IPs on the servers on that VLAN"

                    What???

                    Dude post your freaking rules please… If you set a gateway on your 1 rule then no your not going to be able to get to your other network... Put a rule above it that allows access to the other network before you send traffic out a gateway..  The link Derelict points to goes over this.

                    An intelligent man is sometimes forced to be drunk to spend time with his fools
                    If you get confused: Listen to the Music Play
                    Please don't Chat/PM me for help, unless mod related
                    SG-4860 24.11 | Lab VMs 2.8, 24.11

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                    • F
                      FauxShow
                      last edited by

                      The bypassing policy routing makes sense if I had other rules with different gateways, which I don't. It's just a VPN with 0.0.0.0/0 as the remote side.

                      How do I create a remote gateway using routing? IPSec isn't an available interface to apply the gateway on.

                      brb; gotta reboot my pfsense

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                      • F
                        FauxShow
                        last edited by

                        brb; gotta reboot my pfsense

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                        • F
                          FauxShow
                          last edited by

                          I hand out VLANs like Oprah hands out gifts and I also block all traffic to and from the DPRK.

                          brb; gotta reboot my pfsense

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                          • johnpozJ
                            johnpoz LAYER 8 Global Moderator
                            last edited by

                            dude your blocking access to LAN net - so yeah NO shit your not going to be able to go there!!!  And all your other nets!!

                            An intelligent man is sometimes forced to be drunk to spend time with his fools
                            If you get confused: Listen to the Music Play
                            Please don't Chat/PM me for help, unless mod related
                            SG-4860 24.11 | Lab VMs 2.8, 24.11

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                            • F
                              FauxShow
                              last edited by

                              Trying to reach it from "Desktop"
                              I can access it if I disable the VPN.

                              brb; gotta reboot my pfsense

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                              • johnpozJ
                                johnpoz LAYER 8 Global Moderator
                                last edited by

                                And what is your desktop rules?

                                An intelligent man is sometimes forced to be drunk to spend time with his fools
                                If you get confused: Listen to the Music Play
                                Please don't Chat/PM me for help, unless mod related
                                SG-4860 24.11 | Lab VMs 2.8, 24.11

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                                • F
                                  FauxShow
                                  last edited by

                                  Wide open:

                                  brb; gotta reboot my pfsense

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                                  • DerelictD
                                    Derelict LAYER 8 Netgate
                                    last edited by

                                    IPsec to destination 0.0.0.0/0 is a significant hurdle. That is generally reserved for things like mobile IPsec clients.

                                    Your reply traffic from the PROXY network is probably going out that IPsec tunnel since it matches the traffic selector there.

                                    A simple packet capture on the IPsec interface should confirm.

                                    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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                                    • F
                                      FauxShow
                                      last edited by

                                      How should I be setting it up? Rules for the local subnet(s) with no gateway specified and then a catch-all for everything else could work, but what do I set that gateway to?

                                      brb; gotta reboot my pfsense

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                                      • DerelictD
                                        Derelict LAYER 8 Netgate
                                        last edited by

                                        I can't think of a good workaround.

                                        Like I said, IPsec to destination 0.0.0.0/0 is troublesome if that is not really what you want.  And in your case it is not what you want because you want to carve out exceptions to that.

                                        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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                                        • F
                                          FauxShow
                                          last edited by

                                          So I should submit a bug then, right? More of a new feature I guess.

                                          We are able to do this with Cisco ASAs btw. It's not like I'm just making up networking concepts.

                                          brb; gotta reboot my pfsense

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                                          • DerelictD
                                            Derelict LAYER 8 Netgate
                                            last edited by

                                            Not a bug.

                                            When we get routed IPsec in 2.5-ish it might be possible.

                                            Use an ASA then I guess. FreeBSD IPsec traffic selectors work how they work at this time.

                                            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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