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    Clients behind NAT does not resolve DNS

    Scheduled Pinned Locked Moved NAT
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    • Z
      zozo6015
      last edited by

      Hello,

      I am using pfsense as a gateway for the some servers which has Private network only and I have NAT enabled on the pfsense so that I can still install software on those servers when needed but even if the servers can ping the dns server or any IP from the internet they cannot resolve any domain. Can you please help me figure this issue out asap.

      Thanks in advance
      Peter

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      • M
        muswellhillbilly
        last edited by

        I'm assuming from what you've written that you're saying you can ping external IP addresses but that you can't resolve any domain names. So this is a DNS issue. Have you tested your DNS connectivity by running something like 'nslookup www.google.com 8.8.8.8' from a LAN-based PC? If this resolves correctly, then you have to visit your DNS settings in your DHCP config (assuming you're using DHCP). Otherwise, change the DNS entry on your PC(s) manually to a public DNS server (eg: 8.8.8.8 or 8.8.4.4, etc).

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        • johnpozJ
          johnpoz LAYER 8 Global Moderator
          last edited by

          So are you using pfsense for your dns?  Can pfsense resolve?  Under the diagnostic menu dns lookup

          Are you using the forwarder or the resolver in pfsense?  Is pfsense behind a NAT or does its wan have a public IP?

          Going to have to give us something to work with here..  What rules do you have on your lan network - did you modify them from default and only allow tcp, and your trying to resolve using your isp dns?

          An intelligent man is sometimes forced to be drunk to spend time with his fools
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          • Z
            zozo6015
            last edited by

            All my clients are configured to use public DNS servers like 8.8.8.8 and 8.8.4.4. The pfsense is also configured to use those servers. When I run ping google.com on the client I get after some time that it could not resolve the domain. Unfortunately this is a fresh minimal install and it has no tools like dig or host to run a dns query. Also the IP's are static and not assigned by dhcp.

            Regards,
            Peter

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            • V
              viragomann
              last edited by

              Is DNS access allowed on LAN interface at pfSense?

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              • DerelictD
                Derelict LAYER 8 Netgate
                last edited by

                @zozo6015:

                All my clients are configured to use public DNS servers like 8.8.8.8 and 8.8.4.4. The pfsense is also configured to use those servers. When I run ping google.com on the client I get after some time that it could not resolve the domain. Unfortunately this is a fresh minimal install and it has no tools like dig or host to run a dns query. Also the IP's are static and not assigned by dhcp.

                Regards,
                Peter

                If you want to debug DNS problems you need DNS problem solving tools. Get some.

                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!
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                • M
                  muswellhillbilly
                  last edited by

                  Any Windows or Linux client will have DNS query tools available. So connect one to your LAN and run the nslookup/dig command I mentioned earlier. Target an external DNS server in your query to see whether you get a response. If you can ping 8.8.8.8, for instance, but don't get a reply when running 'nslookup www.google.com 8.8.8.8' then I would look carefully at your firewall rules. If in doubt, post them and maybe someone can help further. Otherwise, I think we've just about exhausted all possibilities at this stage.

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