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    Potential DNS Rebind attack detected on my local network

    Scheduled Pinned Locked Moved General pfSense Questions
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    • johnpozJ
      johnpoz LAYER 8 Global Moderator @stephenw10
      last edited by

      @stephenw10 yeah you would expect tardis. to fail with dig.. that is asking for just tardis and not fully qualified, that should always fail.

      if your going to use nslookup and let the search suffix work you should set debug so you can see what it actually asks for.

      Your ping there on windows that comes back without it fully qualified is most likely using something else to resolve mdns, llmns, wds - there are multiple methods of just resolving locally without dns. If it actually used dns to resolve that than the ping should show tardis.home.arpa, etc..

      ash-4.4# nmblookup i9-win
      192.168.10.9 i9-win<00>
      192.168.9.100 i9-win<00>
      172.29.64.1 i9-win<00>
      ash-4.4# 
      

      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 comet424

        @johnpoz
        @stephenw10

        so not sure how to use the debug for for nslookup well properly the way you guys want me to type it in
        as for domain name. i only have it set under general.

        so its weird i always thought that as long as i could ping a hostname in windows that the dns was working but it used mdns llmns wds or so on.. always learn something new everyday no wonder i had probems 25 years ago witn WinGate trying to share internet was a program to share internet and dns server...

        so i did a bunch of tests and screen shots of my static ip the dhcp of lan general... do you see anything i got set wrong that that dns resolver isnt working right.. does NAT have anything to do with it?
        is there another place to look for domain name or page that the resolver isnt working.. i figured the extra PIA NATs i added duplicated of the WAN as i dunno i did a clean install last time i had issues and seems i got issues again lol its just just 1 check box or 1 rule that causes the dns not to work

        digg1.png digg2.png digg3.png digg4.png digg5.png digg6.png digg7.png digg8.png digg9.png digg10.png
        digg11.png
        nat1.png nat2.png nat3.png

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

          @comet424 I am not sure what is going on but what does yours show when you go to the dns lookup under diagnostics?

          lookup.jpg

          what about dig right on pfsense?

          [24.03-RELEASE][admin@sg4860.home.arpa]/root: dig nas.home.arpa
          
          ; <<>> DiG 9.18.20 <<>> nas.home.arpa
          ;; global options: +cmd
          ;; Got answer:
          ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 41317
          ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
          
          ;; OPT PSEUDOSECTION:
          ; EDNS: version: 0, flags:; udp: 4096
          ;; QUESTION SECTION:
          ;nas.home.arpa.                 IN      A
          
          ;; ANSWER SECTION:
          nas.home.arpa.          3600    IN      A       192.168.9.10
          
          ;; Query time: 0 msec
          ;; SERVER: 127.0.0.1#53(127.0.0.1) (UDP)
          ;; WHEN: Mon Nov 25 15:33:39 CST 2024
          ;; MSG SIZE  rcvd: 58
          
          [24.03-RELEASE][admin@sg4860.home.arpa]/root: 
          

          What seems really odd to me is that SOA.. you shouldn't be getting that.

          soa.jpg

          unbound is not an authoritative NS, it really shouldn't hand out SOAs for domain you have records for.. And have no idea where that is coming from.. If your stuff was being forward to any sort of public dns.. Then you should get back that

          SOA prisoner.iana.org.

          if you setup a reservation for this tardis IP via its mac, then on unbound register reservations/static

          static.jpg

          does pfsense.home.arpa resolve via dns diagnostic?

          You can look in your unbound config.

          [24.03-RELEASE][admin@sg4860.home.arpa]/var/unbound: cat host_entries.conf 
          local-zone: "home.arpa." static
          local-data-ptr: "127.0.0.1 localhost.home.arpa"
          local-data: "localhost. A 127.0.0.1"
          local-data: "localhost.home.arpa. A 127.0.0.1"
          local-data-ptr: "::1 localhost.home.arpa"
          local-data: "localhost. AAAA ::1"
          local-data: "localhost.home.arpa. AAAA ::1"
          local-data-ptr: "192.168.9.253 sg4860.home.arpa"
          local-data: "sg4860.home.arpa. A 192.168.9.253"
          local-data-ptr: "192.168.9.10 nas.home.arpa"
          local-data: "nas.home.arpa. A 192.168.9.10"
          local-data-ptr: "192.168.9.100 i9-win.home.arpa"
          local-data: "i9-win.home.arpa. A 192.168.9.100"
          local-data-ptr: "192.168.2.5 FlexHD.home.arpa"
          local-data: "FlexHD.home.arpa. A 192.168.2.5"
          local-data-ptr: "192.168.2.13 UC.home.arpa"
          local-data: "UC.home.arpa. A 192.168.2.13"
          local-data-ptr: "192.168.2.198 Johns-13.home.arpa"
          local-data: "Johns-13.home.arpa. A 192.168.2.198"
          

          Can you post up your /var/unbound/unbound.conf file? If your registering dhcp, and you have a client renew its lease you should see it listed in dhcpleases_entries.conf

          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

            ok so i ran your tests did a couple extras and i did some comments

            hope its helping as i dunno whats wrong from what i see compared to yours dns is not pointing internally but externally for internal ips

            dns lookup.png dns lookup2.png dns lookup3.png

            i ran this before i did the check box register dhcp button you had me do
            dns lookup4.png

            now i checked the register box
            dns lookup5.png dns lookup6.png dns lookup7.png dns lookup8.png

            now i did the dhcp releases one

            dns lookup9.png dns lookup10.png

            now looking at the file i notice it doesnt have all the dhcp leases from the ARP table from diagnostics page.. unless it takes a bit or needs a reboot?

            and dont tell me that one check box solves everything? but hope that info so far helps diginose whats going on and more tests i look forward to solve things

            and i really appreciate you and stephens help

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            • stephenw10S
              stephenw10 Netgate Administrator
              last edited by

              Note you have added the host in the static mapping as Tardis and linux/freebsd is case sensitive here. It should always be all lower case there: tardis.

              johnpozJ 1 Reply Last reply Reply Quote 0
              • johnpozJ
                johnpoz LAYER 8 Global Moderator @stephenw10
                last edited by johnpoz

                @stephenw10 huh? dns is not case sensitive..

                casew.jpg

                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

                  Mmm I confess I've never tried adding anything upper case as a hostname. But it sure makes me twitch seeing it like that. 😉

                  Edit: I guess I'm twitching unnecessarily here. I would still never use an upper case character though!

                  johnpozJ 1 Reply Last reply Reply Quote 0
                  • johnpozJ
                    johnpoz LAYER 8 Global Moderator @stephenw10
                    last edited by

                    @stephenw10 yeah I hear yeah, but when you actually do the dns query - it doesn't care.. Even an option for unbound to send the case all crazy like in my example.

                    dns.jpg

                    https://datatracker.ietf.org/doc/html/draft-vixie-dnsext-dns0x20-00

                    so client can ask unbound for something.domain.tld and unbound will resolve it like sOmeTHing.dOmAin.tLd

                    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
                      @stephenw10
                      i tested Tardis and tardis they both work and ubuntu can ping now by the register dhcp resesverations
                      why didnt it work before? i do notice raspberry pi can not ping like pump but ubuntu can ping it

                      its least working

                      do i need to enable Experimental bit 0x20 and what exactly it do

                      also i know i asked for help before etc
                      apparently my bell internet the dns goes down it connects and i can ping like 1.1.1.1 ip address's but not name servers like google.ca so that manes my site to site doesnt work and nore does my vpn as its name not and ip

                      the way i connecting right now is in general settings dns settings
                      i set 1.1.1.1 for wan_ppoe
                      as i tried the PIA VPN other 2 dns ips and i guess you need to be logged in to be able to use there dns servers.

                      but when i set it 1.1.1.1 wan_ppoe i can get connected and it leaks dns... is there no way to have 1.1.1.1 wan_ppoe
                      10.0.0.241 PIA_vpn

                      is there no way to have both and yet keep them seperated i tried the no_wan_egrees but no didnt didnt stop cloudfare for being on the PIA vpn so then its not secure

                      i know one of you said thats now how it works the way i thought where 1.1.1.1 would only be used for wan_ppoe and 10.0.0.241 would be used for PIA_vpn it doesnt keep it seperate
                      but right now with my dsl dns servers down for name thats how i get internet to work unless you know IP

                      is there another work around so i can set it for 1.1.1.1 as its not the first time my bell internet dns goes down for names but it connects and only ip address's work but names dont work

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

                        @comet424 resolving local resources that are listed in unbound be it via dhcp registration or static dhcp registration or host overrides has zero to do with any public dns service you would forward too.. They are not going to resolve your local resources, nor should they even i you put records up there because any ns you forward or that is not actually unbound itself that returns a rfc1918 address would be a rebind and is dangerous behavior.

                        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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