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    Weird situation about accessing LAN to DMZ

    Scheduled Pinned Locked Moved General pfSense Questions
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    • V
      VincentEmmanuel @johnpoz
      last edited by

      @johnpoz yeah that was a mistake as we just setup the rules last week, it's supposed to be allowed from lan side only.

      However there's still something wrong with the pfsense routing as

      1. Lan cannot reach dmz in general except the firewall itself
      2. Vpn can reach dmz so it's not the device blocking it.

      Sniff on lan proofs that pfsense did deliver the icmp to dmz but it kinda lost somewhere between pfsense and dmz

      johnpozJ stephenw10S 2 Replies Last reply Reply Quote 0
      • johnpozJ
        johnpoz LAYER 8 Global Moderator @VincentEmmanuel
        last edited by

        @vincentemmanuel said in Weird situation about accessing LAN to DMZ:

        lost somewhere between pfsense and dmz

        you sure you don't have the mask wrong on the dmz device.. If the mask is wrong and it thinks the lan IP is on its own network then no it wouldn't work, but if the vpn IP is different then that would work.

        An intelligent man is sometimes forced to be drunk to spend time with his fools
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        • V
          VincentEmmanuel @johnpoz
          last edited by

          @johnpoz yes, the mask is not wrong. Can we add a custom route to force this?

          bingo600B 1 Reply Last reply Reply Quote 0
          • bingo600B
            bingo600 @VincentEmmanuel
            last edited by

            @vincentemmanuel
            My suggestion is to solve the root cause , not work around it.

            Since LAN and DMZ both are "Connected interfaces" , there should be no need for an additional route. Which btw. would have a lower routing priority than a Connected Interface.

            If by any chance an added route would somehow solve the issue, it would clearly indicate a configuration error in the setup.

            /Bingo

            If you find my answer useful - Please give the post a šŸ‘ - "thumbs up"

            pfSense+ 23.05.1 (ZFS)

            QOTOM-Q355G4 Quad Lan.
            CPUĀ  : Core i5 5250U, Ram : 8GB Kingston DDR3LV 1600
            LANĀ  : 4 x Intel 211, DiskĀ  : 240G SAMSUNG MZ7L3240HCHQ SSD

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            • V
              VincentEmmanuel @bingo600
              last edited by

              @bingo600 Yes. I wanted to solve this root cause but I have run out of options because like you say they are connected interfaces and if LAN is already set to any any rules, there is no reason why it cannot access the DMZ servers.

              I have 2 WAN gateways, but that should be something out of this context.

              Any other suggestions are welcome.

              bingo600B johnpozJ 2 Replies Last reply Reply Quote 0
              • bingo600B
                bingo600 @VincentEmmanuel
                last edited by bingo600

                @vincentemmanuel

                You should upload a bit more info , like the interface settings , route table and arp table (after pinging default-gw , from both LAN & DMZ).

                And elaborate if you have made other NAT/Portforward rules.

                Output from an ipconfig & route from a DMZ n server wouldn't be bad too.

                Edit: Your servers aren't multihomed , are they ? - Multi active NIC's ?

                /Bingo

                If you find my answer useful - Please give the post a šŸ‘ - "thumbs up"

                pfSense+ 23.05.1 (ZFS)

                QOTOM-Q355G4 Quad Lan.
                CPUĀ  : Core i5 5250U, Ram : 8GB Kingston DDR3LV 1600
                LANĀ  : 4 x Intel 211, DiskĀ  : 240G SAMSUNG MZ7L3240HCHQ SSD

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                • johnpozJ
                  johnpoz LAYER 8 Global Moderator @VincentEmmanuel
                  last edited by

                  @vincentemmanuel not sure how you think its a routing issue?

                  You stated you see pfsense sending on the ping.. This isn't a pfsense problem - this is problem with your device. If your saying the mask is correct, then the next logical thing is firewall.

                  So you see pfsense sending on the ping, but you get no response - how would putting some "route" on pfsense fix that?

                  @bingo600 brings up some good questions, are we missing a piece of the puzzle here? Like multihomed device in the dmz?

                  So why don't you again prove it to yourself and sniff on the device in the dmz your trying to ping.. Do you see it get the pings? If not then clearly they are being blocked/dropped somewhere between pfsense interface that you saw the pings leave via your sniff, and the device.

                  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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                  • stephenw10S
                    stephenw10 Netgate Administrator @VincentEmmanuel
                    last edited by

                    @vincentemmanuel said in Weird situation about accessing LAN to DMZ:

                    Sniff on lan proofs that pfsense did deliver the icmp to dmz but it kinda lost somewhere between pfsense and dmz

                    What about a pcap on DMZ? Does that show the ping leaving the DMZ interface toward the servers but no reply?

                    Do you see the servers ARPing for the LAN clients maybe?

                    What subnets are in use here exactly?
                    LAN is 192.168.9.0/24?
                    DMZ is 192.168.3.0/24?
                    What is the VPN subnet?

                    You could workaround this with an outbound NAT rule on DMZ but you absolutely shouldn't have to do that.

                    Steve

                    johnpozJ 1 Reply Last reply Reply Quote 0
                    • johnpozJ
                      johnpoz LAYER 8 Global Moderator @stephenw10
                      last edited by

                      @stephenw10 said in Weird situation about accessing LAN to DMZ:

                      What about a pcap on DMZ?

                      That is where I told him to sniff from the get go, that is where he took the sniff I would of thought, taking it on lan is sure a valid check that pfsense is even seeing the ask for ping to dmz device. But the whole point was to validate pfsense is sending on the traffic.

                      Sniff on lan proofs that pfsense did deliver the icmp to dmz

                      But I can see how this could be misleading... Where exactly was the sniff taken? But his lan rules show no policy routing so its not like pfsense sending it out some gateway if sees it on lan, unless there is a floating rule that either blocks it or policy routes the traffic.

                      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
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                      • stephenw10S
                        stephenw10 Netgate Administrator
                        last edited by

                        Indeed, I'd be surprised if it wasn't leaving the DMZ. It's almost certainly an issue at the target server.
                        But it could be some NAT rule or IPSec perhaps.

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                        • V
                          VincentEmmanuel
                          last edited by

                          Thanks guys! Let me try my best to provide the details

                          LAN 10.65.1.0/24
                          DMZ 172.16.65.0/24
                          VPN 10.5.5.0/24

                          I have an IOT network at 10.65.2.0/24

                          I have 5 servers in the DMZ with IP ending 11 20 25 30.
                          NAT 1:1
                          Not multihomed.

                          Things I have done.
                          Turning off DNS resolver so that LAN access server via public IP (failed)
                          Capture Packet from LAN interface (ICMP sent successfully from pfsense)
                          Capture Packet from DMZ interface (No ICMP traffic from my LAN host)

                          Yesterday I did a test, I swop LAN with IOT and now everything works.

                          I am not sure what is the root problem but I can conclude it is not the end devices and probably the "LAN" on pfsense has some special thing going on.

                          johnpozJ stephenw10S 2 Replies Last reply Reply Quote 0
                          • johnpozJ
                            johnpoz LAYER 8 Global Moderator @VincentEmmanuel
                            last edited by

                            @vincentemmanuel do you have some rules you didn't show us on the lan? Above that any rule? Do you have rules in floating.

                            Like maybe block rfc or bogon ;) Have seen that countless times.. That is why it is always best to show full rule sets, not just some specific rule. From the posting you have on your lan above - that would allow all traffic and not send it out some gateway.

                            But for all we know you have block rfc or some other rule policy routing traffic? Also do you have any rules in floating tab?

                            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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                            • V
                              VincentEmmanuel @johnpoz
                              last edited by

                              @johnpoz Well I didnt show the entire LAN ruleset because during troubleshooting I moved the any any rules to the top so the rest didn't really matters since everything passed thru that.

                              As for the floating rules, here it is

                              e6635333-17d7-4b51-80e3-daf18833f364-image.png

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                              • johnpozJ
                                johnpoz LAYER 8 Global Moderator @VincentEmmanuel
                                last edited by johnpoz

                                @vincentemmanuel well floating wouldn't have any issues. What other rules did you have on lan that you moved. If you had created a state, that say for example sent it out a vpn interface or something, that could cause the issue.

                                Here is the thing, if your rules allowed access on lan, and you were not forcing it out a gateway, there would be nothing stopping the traffic from going out the interface the destination IP was meant for. Basic routing, pfsense has routes for all the networks its directly attached to.

                                The only other thing that would stop it from sending on the traffic would be if it didn't know the mac address of the IP your trying to send to. Since its directly attached to that network.

                                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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                                • stephenw10S
                                  stephenw10 Netgate Administrator @VincentEmmanuel
                                  last edited by

                                  @vincentemmanuel said in Weird situation about accessing LAN to DMZ:

                                  Yesterday I did a test, I swop LAN with IOT and now everything works.

                                  What exactly did you swap? The NIC assignment?

                                  When traffic seems to disappear like that my prime suspect is always IPSec. Do you have any IPSec tunnels configured?

                                  Steve

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                                  • V
                                    VincentEmmanuel @stephenw10
                                    last edited by

                                    @stephenw10 yes. I swopped the nic assignment. I do have ipsec tunnel configured but how would that affect the lan traffic to Dmz?

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                                    • stephenw10S
                                      stephenw10 Netgate Administrator
                                      last edited by

                                      If an IPSec P2 config is over-matching it will grab that traffic and send it across the tunnel so it never reaches the DMZ.
                                      That affect it whatever the NIC assignment though. It only applies to subnets.

                                      Steve

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