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    [RESOLVED]No internet on ubuntu when disable dhcp

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    • F
      Farisse @bmeeks
      last edited by

      @bmeeks
      Thank you for your answer
      Indeed, i have to use the dns of the school. But what i don't understand is, i don't put anything on my windows machine except the static ip, gateway that's all and it works. But on my ubuntu machine it doesn't work. So i don't understand how it works in pfsense to let my windows machine use the dns i entered in pfsense and not my ubuntu machine. It's not logic for me :/

      bmeeksB 1 Reply Last reply Reply Quote 0
      • bmeeksB
        bmeeks @Farisse
        last edited by

        @Farisse said in No internet on ubuntu when disable dhcp:

        @bmeeks
        Thank you for your answer
        Indeed, i have to use the dns of the school. But what i don't understand is, i don't put anything on my windows machine except the static ip, gateway that's all and it works. But on my ubuntu machine it doesn't work. So i don't understand how it works in pfsense to let my windows machine use the dns i entered in pfsense and not my ubuntu machine. It's not logic for me :/

        Is your Windows machine a member of an AD domain? If so, the AD domain controller is the DNS server, and it probably forwards to the school's DNS server (or it may actually be the school's DNS server).

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        • F
          Farisse @bmeeks
          last edited by

          @bmeeks Nope its not :(
          I just tried but my windows machine is not member of AD domain.
          here is a little video : https://streamable.com/6mznjo
          even with the schools dns it doesn't work anymore. Really strange things are happening here :/

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          • bmeeksB
            bmeeks @Farisse
            last edited by

            @Farisse said in No internet on ubuntu when disable dhcp:

            @bmeeks Nope its not :(
            I just tried but my windows machine is not member of AD domain.
            here is a little video : https://streamable.com/6mznjo
            even with the schools dns it doesn't work anymore. Really strange things are happening here :/

            I am not a user of Hyper-V. I am an ESXi user. One place I would concentrate my research is within the networking configuration of Hyper-V.

            Are you running Hyper-V on hardware by itself, or are you running Hyper-V on say a Windows desktop? There will be substantial changes to some of the networking in one installation versus the other.

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            • F
              Farisse @bmeeks
              last edited by

              @bmeeks
              I don't think the problem should come from the hyper v configuration. I think this because all the other machines are working, and its only ubuntu machines that doesn't work. (Maybe i should go to an ubuntu forum sorry for that). I work on a windows desktop.
              So i have a VPN connection to the windows machine where is installed windows server and hyper-v manager.
              I think the problem should be something like resolving he dns between the ubuntu machine and pfsense but idk where to search :/

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              • F
                Farisse
                last edited by

                After a lot of research i'm asking myself if someone could maybe tell me where i could find any information about the changes that are made when the dhcp server is enabled.

                I searched in the pfsense book, but it is not written how it works. If i find what changes are made i would be able to find where the problem is with my server.

                Thank you guys !

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                • johnpozJ
                  johnpoz LAYER 8 Global Moderator
                  last edited by

                  And again - The dhcp server being on or off has ZERO to do with whatever issue your having.

                  The only changes that happen that you might not see when you enable a dhcp server on a specific interface, is some hidden rules get added to allow for dhcp to reach the server running on pfsense..

                  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 2.7.2, 24.11

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                  • bmeeksB
                    bmeeks
                    last edited by bmeeks

                    Okay, going back and reading your original post one more time, this is what I am hearing you say:

                    When you turn on or enable the DHCP server in pfSense and you enable DHCP in your Ubuntu machine, you have Internet access. But when you turn off the DHCP server in pfSense and try a static IP with no DHCP configured in Ubuntu, you have no Internet access.

                    If the above is correct, then this is what I think is happening. You are never actually disabling the DHCP client on the Ubuntu machine even though you might think you are. So when you turn off the DHCP server in pfSense, the DHCP client on Ubuntu can't get a proper IP address and thus you have no connectivity. With the DHCP server running on pfSense, the Ubuntu DHCP client can get the info it needs and the Internet works on the Ubuntu machine.

                    That's what I believe is happening. You think you are turning off DHCP on the Ubuntu machine and switching to a static IP, but I'm thinking perhaps you are not actually doing that. I know that it can be a real pain to re-plumb the network in modern Linux distros with their fancy GUIs. They really, really want to use the DHCP client.

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                    • F
                      Farisse @johnpoz
                      last edited by

                      @johnpoz You are right, but where could i find these rules ? My firewall rules are empty (or everything is open). There is something i am missing in this configuration. It makes me sick of not understanding why sometimes it works and sometimes not with the same configuration.

                      @bmeeks i actually don't even know when it's working or not. I had a few minutes ago an internet connection on my machine and, a few minutes later nothing anymore.

                      How could i get more details about this ? Logs ?

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

                        @Farisse said in No internet on ubuntu when disable dhcp:

                        My firewall rules are empty (or everything is open)

                        If your firewall rules are EMPTY then everything is blocked!

                        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 2.7.2, 24.11

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                        • F
                          Farisse @johnpoz
                          last edited by

                          @johnpoz No sorry I mean everything is open 74ea0f9a-a7ef-4ac7-bcc2-c1b7bf11f7ec-image.png

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                          • johnpozJ
                            johnpoz LAYER 8 Global Moderator
                            last edited by johnpoz

                            And clearly you have 13 states currently open using that rule, and have moved 63.18 MB of traffic.

                            How about some actual info... Lets see you ping the DMZ address from this client.. Lets see you do a dns query to what the dmz address, some other dns server?

                            Lets see the ifconfig output from this client. When you say it doesn't work, and then when you say it works if you turn on dhcp on pfsense.

                            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 2.7.2, 24.11

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                            • F
                              Farisse @johnpoz
                              last edited by

                              @johnpoz said in No internet on ubuntu when disable dhcp:

                              How about some actual info... Lets see you ping the DMZ address from this client.. Lets see you do a dns query to what the dmz address, some other dns server?
                              Lets see the ifconfig output from this client. When you say it doesn't work, and then when you say it works if you turn on dhcp on pfsense.

                              i am not sure about understanding the questions do you mean that i show the results of the commands you said ?

                              There are 2 dns servers. One one the schools network and the other in my lan network.

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                              • johnpozJ
                                johnpoz LAYER 8 Global Moderator
                                last edited by johnpoz

                                Yes lets see the output of the commands.. Not just you saying something doesn't work via what a browser? ping pfsense dmz address, if you can't then your never getting anywhere.. If you can not query dns then your never going to get anywhere via fqdn.

                                Lets see say a traceroute when it works, and when it doesn't work to both an IP say 8.8.8.8 and then say via a fqdn like www.google.com

                                Your not doing something like static arps are you in pfsense?

                                If you setup a static arp say for 1.2.3.4 mac xyz so that what the client gets when dhcp is on, and then you setup IP on the machine to be 1.2.3.5 then no it wouldn't work.

                                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 2.7.2, 24.11

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                                • F
                                  Farisse @johnpoz
                                  last edited by Farisse

                                  @johnpoz
                                  the video is uploading i'll add screenshots in a few minutes
                                  https://streamable.com/j30bzs

                                  Ping from Windows Hyper-v to DMZ network 455fbd6a-2e49-4aca-9c16-51e06309c41e-image.png

                                  Ping from Ubuntu to DNS/DMZ network + ifconfig
                                  41793422-93b4-41ea-b546-d88f9cc70877-image.png

                                  Do you need more info ?

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                                  • johnpozJ
                                    johnpoz LAYER 8 Global Moderator
                                    last edited by

                                    And that is with dhcp or static? And where is your dns query?

                                    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 2.7.2, 24.11

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                                    • F
                                      Farisse
                                      last edited by Farisse

                                      This is Static the video is when internet was functional and then after reboot ... nothing anymore

                                      here is the dns query:
                                      c3cd78d9-8c96-438e-890e-4835863518f0-image.png

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                                      • johnpozJ
                                        johnpoz LAYER 8 Global Moderator
                                        last edited by johnpoz

                                        Well not really possible to use the internet without dns resolution..

                                        What server are you trying to query - can not tell from that command..

                                        Do a dig with with @ipaddress of dns server.

                                        something like dig @192.168.1.1 www.google.com

                                        your command is just going to ask some dns server, which don't know what that is for 192.168.1.1

                                        Is pfsense listening on dmz interface for dns? Are you pointing dns to something else?

                                        how about this output

                                        networkctl status
                                        ●        State: routable
                                               Address: 192.168.2.12 on ens3
                                                        fe80::11:32ff:fe22:cc7d on ens3
                                               Gateway: 192.168.2.253 (ADI Engineering, Inc.) on ens3
                                                   DNS: 192.168.3.10
                                        Search Domains: local.lan
                                                   NTP: 192.168.3.32
                                                        192.168.2.253
                                        

                                        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 2.7.2, 24.11

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                                        • F
                                          Farisse @johnpoz
                                          last edited by

                                          @johnpoz Well i didn't change anything and i have an internet connection again.

                                          maybe extra information :
                                          I use an external DNS in pfsense
                                          25f8f886-96b7-48a5-ad05-9bf473fc797e-image.png

                                          As from now i have internet this is the requested command :
                                          2e919bed-ce19-4c6b-a4c7-be3a8079fe0c-image.png

                                          cdea2864-c329-4214-bd3d-60812506f9b0-image.png

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                                          • johnpozJ
                                            johnpoz LAYER 8 Global Moderator
                                            last edited by

                                            Well from your output of nteworkctl you have NO DNS set..

                                            Unless you setup forwarding on pfsense, those dns servers don't do anything other what pfsense itself would use for dns.

                                            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 2.7.2, 24.11

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