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    [RESOLVED]No internet on ubuntu when disable dhcp

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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
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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 ?

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          • 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!

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            If you get confused: Listen to the Music Play
            Please don't Chat/PM me for help, unless mod related
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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
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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 2.8, 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 2.8, 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 2.8, 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 2.8, 24.11

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                                • F
                                  Farisse
                                  last edited by

                                  The DNS forwarder is indeed enabled in pfsense and dns resolver to. Does it make any change if i configure the dns on a client machine ?

                                  And why do i get internet for a few time then no more internet and after a few time back again without changing nothing ?

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                                  • johnpozJ
                                    johnpoz LAYER 8 Global Moderator
                                    last edited by

                                    My "guess" would be when your on dhcp you cache some records..

                                    Clearly from what you posted you have no dns set.. So NO internet is never going to work - unless you plan on just using IPs only ;)

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

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

                                      The DNS forwarder is indeed enabled in pfsense and dns resolver to

                                      Well that is just borked! You mean you have unbound fowarding? Running both forward (dnsmasq) and resolver unbound is going to be problematic for sure.. Unless you have 1 running on different port than 53.

                                      from your directed query to 192.168.1.1 you resolved google - so set your ubuntu to use that for its dns when you run static.

                                      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
                                        Farisse
                                        last edited by

                                        They are on two different ports
                                        92a0187a-0d46-47c6-81eb-425c49f9b715-image.png
                                        90899a5d-f29b-4944-bfaa-6c614e19fe02-image.png

                                        I should normally not have any problem with that ? Except maybe my other dns server who is in my lan that i use with freeradius on my guest network ?

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                                        • F
                                          Farisse @johnpoz
                                          last edited by

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

                                          from your directed query to 192.168.1.1 you resolved google - so set your ubuntu to use that for its dns when you run static.

                                          What do you mean with this ? I thought i already configures my ubuntu for using a dns ?
                                          c6e5b648-ab3c-49db-9213-05f9dfa9cf4d-image.png
                                          286efefb-6daa-4f00-af26-9316acdd2e85-image.png

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                                          • johnpozJ
                                            johnpoz LAYER 8 Global Moderator
                                            last edited by johnpoz

                                            Well clearly not using that now is it..

                                            When you directed to do dns it work @192.168.1.1

                                            When you just do dig, its saying it can not talk to dns.

                                            when you look with networkctrl status - does it show you dns.. NO... And its not working, so clearly its NOT SET!! if it was, then it would be using it and working...

                                            what does nslookup show you?

                                            user@NewUC:~$ nslookup www.google.com
                                            Server:         127.0.0.53
                                            Address:        127.0.0.53#53
                                            
                                            Non-authoritative answer:
                                            Name:   www.google.com
                                            Address: 172.217.4.196
                                            Name:   www.google.com
                                            Address: 2607:f8b0:4009:806::2004
                                            
                                            

                                            Here
                                            https://linuxize.com/post/how-to-configure-static-ip-address-on-ubuntu-18-04/

                                            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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