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    DNS doesn't work after switch layer 3 inter vlan routing upgrade

    Scheduled Pinned Locked Moved DHCP and DNS
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    • C
      chiprule
      last edited by

      Hi Team,
      I update my cisco sg300 switch in layer 3 mode.
      For now I only configure 2 VLAN on cisco switch for test purposes.
      Vlan 1 - int 172.16.1.254/24
      Vlan 50 - int 10.0.50.1/24
      My pfsense LAN ip is 172.16.1.1

      I put lan cable from PFsense Lan to cisco switch and configure it in access mode vlan1.
      I follow this steps https://greigmitchell.co.uk/2019/08/configuring-intervlan-routing-with-a-layer-3-switch-and-pfsense/

      Now i can ping from vlan 1 to vlan 50 and viceversa.
      I can ping PFsense LAN IP interfaces from both vlan.
      I can ping 8.8.8.8 from both vlan.
      I can go in internet with vlan 1 but not with vlan 50.

      I set 172.16.1.1 as DNS server in clients of vlan 50

      It seem to be a DNS problem. I can't figure out what is the missing or wrong config.

      Thanks

      JKnottJ 1 Reply Last reply Reply Quote 0
      • JKnottJ
        JKnott @chiprule
        last edited by

        @chiprule

        Have you set up routing for VLAN 50?

        PfSense running on Qotom mini PC
        i5 CPU, 4 GB memory, 32 GB SSD & 4 Intel Gb Ethernet ports.
        UniFi AC-Lite access point

        I haven't lost my mind. It's around here...somewhere...

        C 1 Reply Last reply Reply Quote 0
        • C
          chiprule
          last edited by chiprule

          Hi @JKnott
          Yes
          9f21955e-f2d2-461b-8f37-b2a97b9c7ec4-image.png

          8ca6d482-aa56-4786-8c91-2dd9dd96a5c5-image.png

          1 Reply Last reply Reply Quote 0
          • C
            chiprule @JKnott
            last edited by

            @JKnott
            63a47753-91eb-47fe-9486-3f1e08c0cd96-image.png

            ed60c7a6-21c0-482e-a8d1-d5258303b2c0-image.png

            JKnottJ 1 Reply Last reply Reply Quote 0
            • JKnottJ
              JKnott @chiprule
              last edited by

              @chiprule

              What does traceroute show? Also, why are you hiding the monitor IP? That shouldn't be your assigned address. It could be your ISPs gateway, DNS server or some other publicly reachable address.

              PfSense running on Qotom mini PC
              i5 CPU, 4 GB memory, 32 GB SSD & 4 Intel Gb Ethernet ports.
              UniFi AC-Lite access point

              I haven't lost my mind. It's around here...somewhere...

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

                If your vlan 50 devices can not query your dns on 172.16.1.1 - most likely its the ACLs.. So ACLs for network directly connected to pfsense get auto created... But when your doing downstream networks, you would have to allow those queries via your ACLs setup in unbound.

                Also I want to warn you up front about doing this - see this all the time... Do you plan on having devices on this 172.16.1 network? If so your most likely going to run into asymmetrical routing problems..

                If you want to do downstream router - that is fine, but it needs to be a pure transit network that connects pfsense to your downstream router.. If your going to put hosts on this transit network, then you need to host route on those devices or you will end up with asymmetrical issues if these hosts are going to talk to downstream networks, or downstream networks are going to be talking to them.

                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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                • C
                  chiprule
                  last edited by

                  Hi @JKnott and @johnpoz ,
                  Thanks for yours prompt reply.
                  This is traceroute from vlan 50
                  tracert.PNG
                  Hiding it comes to me automatically :) this is lab enviroment and WAN IP is assigned by ISP dhcp, no reason at all for hiding. I fell sorry if you interpreted as a lack of trust.

                  I assigned ACL on LAN interface for this subnet
                  040e9383-6e31-4a02-b487-5e0e8ae249c9-image.png

                  f3055e72-f199-4563-baa9-4dca4d07c375-image.png
                  My goal is to use subnet 172.16.1.1 only as a transit network and shrink it from /24 to /30.
                  Anyway thanks for your advice to not use 172.16.1.1 as vlan for hosts.

                  I appreciate your help

                  JKnottJ 1 Reply Last reply Reply Quote 0
                  • JKnottJ
                    JKnott @chiprule
                    last edited by

                    @chiprule said in DNS doesn't work after switch layer 3 inter vlan routing upgrade:

                    This is traceroute from vlan 50

                    I thought your problem was reaching VLAN 50. Why are you showing a traceroute from it to the Internet?

                    PfSense running on Qotom mini PC
                    i5 CPU, 4 GB memory, 32 GB SSD & 4 Intel Gb Ethernet ports.
                    UniFi AC-Lite access point

                    I haven't lost my mind. It's around here...somewhere...

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

                      Not talking about you rules on your interface - talking about your unbound ACLs

                      acls.jpg

                      The auto rules create rules for the local attached networks, but will not work for downstream networks.. You would have to create acl to allow your 50 vlan to query dns..

                      Simple dig would show you not working or working..

                      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

                      1 Reply Last reply Reply Quote 1
                      • C
                        chiprule
                        last edited by

                        Hi @JKnott
                        As I said in first post
                        "Now i can ping from vlan 1 to vlan 50 and viceversa.
                        I can ping PFsense LAN IP interfaces from both vlan.
                        I can ping 8.8.8.8 from both vlan.
                        I can go in internet with vlan 1 but not with vlan 50."

                        "It seem to be a DNS problem. I can't figure out what is the missing or wrong config."

                        @johnpoz
                        0206f6a6-4996-487d-97ec-c36c83a5bcb2-image.png

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

                          Exactly - so since this network is not directly attached - your auto rules will not allow you to query dns..

                          unboundadvanced.jpg

                          I turn off auto rules - because I hate auto rules ;) hehehe The lets me assign the acls I want specifically vs the auto... But out of the box it only creates acls that allow your locally attached networks to query unbound.. Which you downstream vlan 50 is NOT!!! Simple query would of showed you refused!

                          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

                          1 Reply Last reply Reply Quote 0
                          • C
                            chiprule
                            last edited by

                            Hi @johnpoz
                            You solve my problem!!!
                            I'm new on PFsense and I'm learning. What do you mean of query? Query from host of vlan 50? You mean nslookup?

                            Thanks

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

                              Yeah a dns query.. looking up something.domain.tld, ie www.google.com - this is a dns query..

                              Doing that with your fav dns tool, dig, host, sure even nslookup - which is pretty useless unless in full debug mode (set debug) would of shown you a refused response..

                              This isn't pfsense stuff - that is just basic dns stuff..

                              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

                              1 Reply Last reply Reply Quote 0
                              • C
                                chiprule
                                last edited by

                                Hi @johnpoz
                                thanks for your help, I appreciate it!

                                1 Reply Last reply Reply Quote 0
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