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    Potential DNS Rebind attack detected on my local network

    Scheduled Pinned Locked Moved General pfSense Questions
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    • stephenw10S
      stephenw10 Netgate Administrator
      last edited by

      It looks like you made it work by removing the search domain from the client so it really is trying to resolve just 'tardis'. But some (many?) devices won't allow that.

      You should send the local domain via DHCP and then set the host overides using that domain.

      In Ubuntu you may need to flash the local resolver cache: sudo resolvectl flush-caches

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        comet424 @stephenw10
        last edited by

        @stephenw10 ah ok so i set the dhcp server domain i put in home.arpa
        and i rebooted the ubuntu desktop but still up able to ping tardis
        i can ping www.google.ca that has no problem it cant ping locally

        so you mean many devices wont allow you to ping tardis or like ping camera10
        as example or all my ESP32 devices that run esphome

        as for the host override... how do i blank host override to add domain and covers everything on the network.. as so far i only learned you can do like 1 ip address at a time

        and i read about split dns and 1:1 nat but all i remember is when i defaulted a clean pfsense i could ping ubuntu and stuff but now where i added vpn and the 1::128 and all those other nats i also wondered if those conflict?

        but so far i can ping from
        raspberry pi
        unraid
        windows
        pfsense

        but i cant seem to ping from any of my ubuntu vms

        and i thought if i set dns 192.168.0.1 and in the resolver i set it to all all for incomming and out going that it would resolve things but i guesss not

        and even after the reboot and the sudo resolvectl flush-caches i still get same error temporary failture..
        i did try this it also failed
        arpa.png

        if you can show with picture how my host override should look like that would cover everything be good as im a visual learner more over then words to understand things

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        • C
          comet424 @comet424
          last edited by

          so i tried these 2 different over rides but these didnt work
          domain.png host.png

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          • C
            comet424 @comet424
            last edited by comet424

            so with those 2 overrides i have i still can ping from
            unraid
            windows

            but
            ubutunu
            raspberry pi

            gives me issues cant resolve it... is that what you ment many cant resolve tardis just hostname

            but what i dont understand is
            i tell dhcp that the dns 192.168.0.1 so all clients know pfsense is to dns resolve all the local hostnames... i dont understand why it doesnt do it least not from ubuntu and raspberry pi.. and now i said that the domain that 192.168.0.1 the dns resolver needs to resolve all but it doesnt seem to be working

            and here the arpa list the ubuntu desktop doesnt have no .home.arpa.. or the example i gave hell.com so pfsense should be resolving the hostnames no matter what os im pinging from right? least thats how i thought it works
            dhcpa.png
            dhcpab.png

            i tried custom options

            server:
            private-domain: "home.arpa"
            

            that didnt help either

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            • stephenw10S
              stephenw10 Netgate Administrator
              last edited by

              In the host override you have to add both the host and the domain. In your example you have added a hostoverride with no host!

              Domain overrides point to a specific DNS server for the whole domain. You don't want that here.

              Try using dig in ubuntu so you know it's actually querying Unbound in pfSense.

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                comet424 @stephenw10
                last edited by

                @stephenw10
                ok so remove the host and domain override.. i did the domain and pointed it to 192.168.0.1 so it would do all local hostnames least thats how i thought

                what about that private-domain i added too how does that work?

                as for ubuntu and dig command these are the screen shots
                i thought once u tell dhcp dns is 192.168.0.1 all OSs would be resolved by pfsense
                ub1.png ub2.png ub3.png

                johnpozJ 1 Reply Last reply Reply Quote 0
                • johnpozJ
                  johnpoz LAYER 8 Global Moderator @comet424
                  last edited by

                  @comet424 that is not what he meant by a dig..

                  dig tardis.home.arpa

                  Your linux is using a local cache, that is why it points to127.0.0.53, if you want to know where that points.

                  user@UC:~$ resolvectl status
                  Global
                         Protocols: -LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported
                  resolv.conf mode: stub
                  
                  Link 2 (ens3)
                      Current Scopes: DNS
                           Protocols: +DefaultRoute +LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported
                  Current DNS Server: 192.168.3.10
                         DNS Servers: 192.168.3.10
                          DNS Domain: home.arpa
                  user@UC:~$ 
                  

                  Private-domain sets a domain so that if you forward for that domain it will turn off rebind protection

                  You are making this so freaking difficult.. Out of the box dhcp will hand out the domain is set in general setup, ie home.arpa for example.. Your client may or may not use that..

                  When you query for dns, it has to be fully qualified, so either query the fqdn - ie tardis.home.arpa or make sure your client is using search suffix and will auto add it for you.

                  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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                  • C
                    comet424 @johnpoz
                    last edited by

                    @johnpoz
                    sorry not trying to make it complicated.. all i thought is once you set it up in pfsense under dhcp server
                    your gate way and dns.. then pfsense did all the resolving of the local hostnames for any operating system.. i not familar with ubuntu alot so i just noticed i cant ping ill have to look up what a fqdn is

                    and all i want is once dhcp server shells out the ip then it doesnt matter what os... just be able to ping and access by the hostname in the arpa table so whatever i have to do to make it auto work like it auto works in unraid and windows.. but then you mention windows does its own thing

                    as for the dig and resolvectl this is the result
                    ub4.png

                    johnpozJ 1 Reply Last reply Reply Quote 0
                    • stephenw10S
                      stephenw10 Netgate Administrator
                      last edited by

                      Try: dig @192.168.0.1 tardis.home.arpa.

                      In that example:

                      tardis is a hostname

                      home.arpa is a domain

                      tardis.home.arpa is a fully qualified domain name (fqdn).

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                      • johnpozJ
                        johnpoz LAYER 8 Global Moderator @comet424
                        last edited by johnpoz

                        @comet424 did you leave that domain forward in there - that is pointless, and prob going to break it.

                        Unless your register dhcp or static reservations. Unbound doesn't have a clue about other hosts you have on your network.

                        So you would either need to do one of those or both, and or just create a host override..

                        tardis.jpg

                        is 192.168.0.1 pfsense IP? Or some other NS?

                        Unbound wouldn't normally return a SOA like that.

                        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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                          comet424 @johnpoz
                          last edited by comet424

                          @johnpoz
                          so i removed that domain and host override yesterday... only thing for domain i left i guess i should remove is

                          server:
                          private-domain: "home.arpa"
                          

                          i can delete that

                          192.168.0.1 is pfsense 192.168.0.3 is the tardis
                          so host overide.. so i have to manaully enter then 200+ ips for ubuntu to be able to access them then ? like i always though under the ARP table the host name you could always ping or access the device by the hostname thats how i do it in unraid or windows like my 30+ ESP devices or all my IOT devices just access them by the Hostname through windows browser or ssh etc..

                          what is a SOA?

                          @stephenw10
                          this is the result of the dig @192.168.0.1 tardis.home.arpa.

                          ub5.png
                          arp1.png

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                          • johnpozJ
                            johnpoz LAYER 8 Global Moderator @comet424
                            last edited by johnpoz

                            @comet424 SOA is a record saying hey have no record of that - you should prob go ask the SOA (source of authority).. Out of the box unbound wouldn't return that record.. you would of had to create it.

                            If in the default transparent mode and you ask for anything.home.arpa and there is no record it would try and resolve it upstream, and that wouldn't return that soa either.

                            for home.arpa that you tried to resolve and had no record of and got sent upstream the soa would be

                            ;; QUESTION SECTION:
                            ;fsljfdsdf.home.arpa.           IN      A
                            
                            ;; AUTHORITY SECTION:
                            home.arpa.              3600    IN      SOA     prisoner.iana.org. hostmaster.root-servers.org. 1 604800 60 604800 604800
                            

                            what do you have in the custom box of unbound? Do you have some host overrides setup.. domain overrides? unbound would not return that nobody soa

                            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 @comet424
                              last edited by

                              @comet424 said in Potential DNS Rebind attack detected on my local network:

                              @stephenw10
                              this is the result of the dig @192.168.0.1 tardis.home.arpa.

                              Sorry that last . was outside the quote! Muscle memory forced me to type it. 😉

                              The command should be:

                              dig @192.168.0.1 tardis.home.arpa

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                              • johnpozJ
                                johnpoz LAYER 8 Global Moderator @stephenw10
                                last edited by

                                @stephenw10 that wouldn't matter, and dig does it by default anyway unlike nslookup

                                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
                                  last edited by stephenw10

                                  Given the presence of Nord and PIA do you have Unbound in forwarding mode to other upstream servers over the VPN?

                                  None of that should matter though, Unbound should still respond with hostoverrides in place.

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                                    comet424 @stephenw10
                                    last edited by comet424

                                    @stephenw10
                                    @johnpoz
                                    so for custom options in dns resolver i have

                                    server:
                                    local-zone: "windowsupdate.com" redirect
                                    local-data: "windowsupdate.com 86400 IN A 192.168.0.32"
                                    
                                    server:
                                    local-zone: "microsoft.com.edgesuite.net" redirect
                                    local-data: "microsoft.com.edgesuite.net 86400 IN A 192.168.0.32"
                                    
                                    server:
                                    local-zone: "update.microsoft.com" redirect
                                    local-data: "update.microsoft.com 86400 IN A 192.168.0.32"
                                    
                                    server:
                                    local-zone: "do.dsp.mp.microsoft.com" redirect
                                    local-data: "do.dsp.mp.microsoft.com 86400 IN A 192.168.0.32"
                                    
                                    server:
                                    local-zone: "dl.delivery.mp.microsoft.com" redirect
                                    local-data: "dl.delivery.mp.microsoft.com 86400 IN A 192.168.0.32"
                                    
                                    server:
                                    local-zone: "cdn.blizzard.com" redirect
                                    local-data: "cdn.blizzard.com 86400 IN A 192.168.0.32"
                                    
                                    server:
                                    private-domain: "home.arpa"
                                    
                                    server:include: /var/unbound/pfb_dnsbl.*conf
                                    

                                    my host over ride is
                                    host1.png host2.png

                                    the
                                    dig @192.168.0.1 tardis.home.arpa command without the extra .

                                    dig.png

                                    dns resolver i set to all all so i can then do the bypass routing policy on Lan
                                    dns1.png

                                    i disabled NordVPN and switched over to PIA they do different things... like no proper video for PIA but one had NAT just 192.168.0.0 and another used the pia for 1::128 and those other generated in NAT table so i dubbed them like i read in a PIA setup tutorial.. its like there is different ways to set up there vpn..

                                    i dont use the DNS forwarder... as it wasnt part of the setup of PIA or norvpn in the past.. and i think i read or watched you cvan have dns resolver and forwarder same time?

                                    only other VPN i use is Site to Site to my sisters Pfsense so i can access her network like it was here.. and i have to re add remote access...

                                    and this is my LAN rules
                                    rules1.png rules2.png

                                    rules3.png
                                    any other screen shots you need..

                                    johnpozJ 1 Reply Last reply Reply Quote 0
                                    • johnpozJ
                                      johnpoz LAYER 8 Global Moderator @comet424
                                      last edited by johnpoz

                                      @comet424 said in Potential DNS Rebind attack detected on my local network:

                                      server:
                                      private-domain: "home.arpa"

                                      that is not needed, like I said that tells unbound hey if I forward home.arpa to some other NS or get an answer from some other ns and the answer is rfc1918 its ok.. But in no scenario that I can think of should that soa be returned for anything in home.arpa domain - unless you created the local record for it.

                                      Or your forwarding to some other NS that has that soa setup or returns that soa for its local records... Unbound sure and the hell does not do that out of that box.

                                      ; <<>> DiG 9.16.50 <<>> @192.168.9.253 home.arpa SOA
                                      ; (1 server found)
                                      ;; global options: +cmd
                                      ;; Got answer:
                                      ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 31045
                                      ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1
                                      
                                      ;; OPT PSEUDOSECTION:
                                      ; EDNS: version: 0, flags:; udp: 4096
                                      ;; QUESTION SECTION:
                                      ;home.arpa.                     IN      SOA
                                      
                                      ;; Query time: 0 msec
                                      ;; SERVER: 192.168.9.253#53(192.168.9.253)
                                      ;; WHEN: Sat Nov 23 12:36:13 Central Standard Time 2024
                                      ;; MSG SIZE  rcvd: 38
                                      

                                      You can see there is no SOA record for home.arpa That tells me unbound is asking something else for home.arpa - or your client isn't actually asking unbound. Or you have a local-data record setup your not showing. You don't have bind package running do you on pfsense?

                                      And if you did ask the public internet for home.arpa or any normal NS on the public internet for something in home.arpa it should return that prisioner soa, because home.arpa has been set aside for private local use only.

                                      Also that you would ever get back a rebind tells me unbound did not return what it had in its local records.. But asked/forwarded to someone else.. A rebind is when unbound asks some other NS and the answer is rfc1918.. That is by definition a rebind.

                                      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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                                      • C
                                        comet424
                                        last edited by

                                        @johnpoz ok ill remove that server private domain then
                                        as for NS thats Name Server right...
                                        and only dns is pfsense minus 192.168.0.32 but thats the lancache for Windows updates and some games.. as my internet is only like 2 megabit and pay 100 bucks a month for internet thats not always stable.. but thats the only DNS stuff i setup

                                        now the only local data setup i setup i guess is under the dhcp server i set static IPs like tardis.. but i set the Tardis hostname and ip of 192.168.0.3 and the DNS 192.168.0.1 and gateway of 192.168.0.1 so i dont do anything fancy

                                        do you need a full display of NAT table.. or my PIA vpn right now i disabled the Nordvpn interface so i was able to shut off the openvpn client...

                                        but ill remove the private domain and do a reboot of pfsense so its fresh.. i sometimes find pfsense works better after a reboot

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                                          comet424 @comet424
                                          last edited by

                                          and i thought i was good everything was find after i changed the general to the home.arpa

                                          and i was able to ping again from Windows and unraid so i thought i was good

                                          but then noticed i couldnt do it from ubuntu or raspberry pi

                                          also i cant ping "tardis" from pfsense ping doesnt allow me there but i was sure i used to be able to

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                                          • stephenw10S
                                            stephenw10 Netgate Administrator
                                            last edited by

                                            You are forwarding requests to whatever DNS servers you have set in System > General Setup via whatever gateways are set there.

                                            But more importantly you don't appear to have any DHCP registration options in the Resolver. So either you are running 24.03 with Kea or pfSense is not the DHCP server on your network?

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