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    Why is it so slow to give an answer from the dns resolver itself ?

    Scheduled Pinned Locked Moved DHCP and DNS
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    • johnpozJ
      johnpoz LAYER 8 Global Moderator @MoonKnight
      last edited by

      You got an answer back from 1.1.1.1 in 3ms? That seems pretty freaking low - are you in the DC where 1.1.1.1 has their services ;)

      An intelligent man is sometimes forced to be drunk to spend time with his fools
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      M 1 Reply Last reply Reply Quote 1
      • M
        MoonKnight @johnpoz
        last edited by MoonKnight

        @johnpoz
        Yeah, it's pretty loud in here šŸ”Š 😁
        I do get 3-4ms most of the time, well that's what DNS Lookup says in my pfSense šŸ˜„
        Maybe i have some misconfiguration in my settings?

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

          @ciscox haha.. I like the loud comment. Only someone that has actually been in a DC prob gets that joke ;)

          I am not a forwarder sort of guy.. I will do my own resolving thank you very much..

          But 3ms is pretty much lan speeds.. So unless something upstream of you caching and intercepting - must be freaking close to one of their pops..

          I am not sure exactly the dns lookup gui php thing does it actual query.. I haven't bothered to look at the code.

          I would think a better test might be to just query directly 127.0.0.1 from console or a client on your lan. And whatever your forwarding to directly and compare.

          But yeah if you ask 127.0.0.1 for something.xyz.tld and it has to forward, its a given that its going to have to be n+x for that response time.. 145 does seem a bit slow.. If your getting a response in 27ms from 1.1.1.1.. But again not exactly sure how that gui look up thing is working.. Maybe it has to wait from time of both of them to response, and they were asked sequentially or something?? I setup forwarding and tested.. and I don't get such a long response from the local.

          forwarding.png

          I would really do a specific query towards 127.0.0.1, and then directed queries towards who your forwarding too.. Once its cached locally doesn't really matter anyway.

          Happy to try and duplicate whatever you might be seeing as a problem.. But like I said, I don't forward - you couldn't ever get me to forward my queries to somewhere else.. When I can resolve what I want directly..

          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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          bingo600B 1 Reply Last reply Reply Quote 0
          • bingo600B
            bingo600 @johnpoz
            last edited by bingo600

            @johnpoz said in [Why is it so slow to give an answer from the dns resolver]

            But like I said, I don't forward - you couldn't ever get me to forward my queries to somewhere else.. When I can resolve what I want directly..

            I'm using forward to my own two local bind9 linux servers 😁

            c3f9eca7-f225-437a-89f1-720ab6be3262-image.png

            It was (in my setup) the only thing that made sense...
            I had a working isc-dhcpd "dhcp" setup (with. a working ddns system) , when
            implementing pfSense.

            And if wanted to resolve ddns , it was easy just to point pfSense at my local bind9's.

            Now i can have ddns resolving , and still avoid setting the dreaded

            947fb0e5-7c66-4db2-bccb-c62daef67b58-image.png

            Else i would totally agree with @johnpoz ...
            Keep your DNS subsystem local , it's actually doing a nice job.
            Except for the dreaded unbound DDNS restarts šŸ¤•

            /Bingo

            If you find my answer useful - Please give the post a šŸ‘ - "thumbs up"

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            • Bob.DigB
              Bob.Dig LAYER 8
              last edited by Bob.Dig

              I am seeing the same here, does look sub optimal.


              Capturbbe.PNG

              @bingo600 Hiding that precious local IPs? šŸ˜‰

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              • bingo600B
                bingo600 @Bob.Dig
                last edited by

                @bob-dig
                Yupp ... Better safe than .....

                If you find my answer useful - Please give the post a šŸ‘ - "thumbs up"

                pfSense+ 23.05.1 (ZFS)

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                Cool_CoronaC 1 Reply Last reply Reply Quote 0
                • Cool_CoronaC
                  Cool_Corona @bingo600
                  last edited by

                  @bingo600 First search gives me long answer times, but subsequent tries to same domain gives me 1 ms since they are getting cached in the DNS resolver.

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                  • bingo600B
                    bingo600 @Cool_Corona
                    last edited by

                    @cool_corona
                    That would w 99% certainty be the same here.
                    Bind9 is caching the ansver.

                    And my guess is that the wife keeps google.com "cached" 😊

                    I use DDGG , but SWMBO wants google.

                    What i meant w. the above was just , that it can be feasible to use forwarders.
                    If one has a reason for.

                    Ie. on the job where pfsense is the main resolver. I was asked (by CORP) to use (forward) to Cisco Umbrella DNS'es. As a security precaution.

                    /Bingo

                    If you find my answer useful - Please give the post a šŸ‘ - "thumbs up"

                    pfSense+ 23.05.1 (ZFS)

                    QOTOM-Q355G4 Quad Lan.
                    CPUĀ  : Core i5 5250U, Ram : 8GB Kingston DDR3LV 1600
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                    Cool_CoronaC 1 Reply Last reply Reply Quote 0
                    • Cool_CoronaC
                      Cool_Corona @bingo600
                      last edited by

                      @bingo600 said in Why is it so slow to give an answer from the dns resolver itself ?:

                      @cool_corona
                      That would w 99% certainty be the same here.
                      Bind9 is caching the ansver.

                      And my guess is that the wife keeps google.com "cached" 😊

                      I use DDGG , but SWMBO wants google.

                      What i meant w. the above was just , that it can be feasible to use forwarders.
                      If one has a reason for.

                      Ie. on the job where pfsense is the main resolver. I was asked (by CORP) to use (forward) to Cisco Umbrella DNS'es. As a security precaution.

                      /Bingo

                      HAHAHAHAHAHAH thats kind a funny....

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                      • P
                        p_bear @bingo600
                        last edited by

                        @bingo600

                        From the pfsense itself:

                        set domain=aliexpress.com
                        dig @9.9.9.9 $domain | grep time
                        ;; Query time: 357 msec
                        dig @1.1.1.1 $domain | grep time
                        ;; Query time: 50 msec
                        dig @127.0.0.1 $domain | grep time
                        ;; Query time: 657 msec
                        
                        set domain=twitter.com
                        dig @9.9.9.9 $domain | grep time
                        ;; Query time: 47 msec
                        dig @1.1.1.1 $domain | grep time
                        ;; Query time: 34 msec
                        dig @127.0.0.1 $domain | grep time
                        ;; Query time: 244 msec
                        

                        If I disable forwarding mode:

                        set domain=twitter.com
                        dig @9.9.9.9 $domain | grep time
                        ;; Query time: 41 msec
                        dig @1.1.1.1 $domain | grep time
                        ;; Query time: 43 msec
                        dig @127.0.0.1 $domain | grep time
                        ;; Query time: 302 msec
                        
                        set domain=aliexpress.com
                        dig @9.9.9.9 $domain | grep time
                        ;; Query time: 52 msec
                        dig @1.1.1.1 $domain | grep time
                        ;; Query time: 34 msec
                        dig @127.0.0.1 $domain | grep time
                        ;; Query time: 112 msec
                        

                        Btw I was using forwarding mode to avoid my ISP from spying me at dns level (with DOT).

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

                          @p_bear said in Why is it so slow to give an answer from the dns resolver itself ?:

                          Btw I was using forwarding mode to avoid my ISP from spying me at dns level (with DOT).

                          You understand with using dot.. The only query from what you gave that would be using DOT would be when you query 127.0.0.1

                          Directed queries or queries showing 1.1.1.1 via the dns gui looking wouldn't be using DOT.. So yeah a DOT query and response is going to be much slower than not using DOT quite often. No matter how much the DOT providers want you to think otherwise ;)

                          You could validate that yourself with simple sniff on wan when you do the queries.. But sure queries via that gui showing some other NS, isn't using DOT.. Let me setup the forwarding again and test that to be sure... But I doubt what the gui shows is via a DOT query when it shows anything other than localhost..

                          I will have to spend a few minutes setting up DOT.. but can tell you for sure pfsense itself does not use dot when talking to nameservers listed in general.. The only way to use dot is via unbound doing the query.. So those queries shown in the gui I find highly highly unlikely that anything other than to localhost could of been done via dot..

                          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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                          • P
                            p_bear @johnpoz
                            last edited by

                            @johnpoz said in Why is it so slow to give an answer from the dns resolver itself ?:

                            You understand with using dot.. The only query from what you gave that would be using DOT would be when you query 127.0.0.1

                            The dns query tool in the Diagnostic menu of course it does not use DOT. It's same when I manually use dig.
                            I'm using DOT for the pfsense DNS resolver.

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

                              Again - that would explain the difference in the query.

                              I ask 1.1.1.1 without dot, its going to be faster than if I ask via dot.. Which is what would be happening via your 127.0.0.1 query

                              Plus you prob have dnssec still selected don't you? Which is pointless if forwarding.. And just going to cause extra traffic. Which will slow down responses

                              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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                              • P
                                p_bear @johnpoz
                                last edited by

                                @johnpoz

                                I've unchecked Use SSL/TLS for outgoing DNS Queries to Forwarding Servers.
                                I still get a difference. :(
                                Capture d’écran 2021-05-10 aĢ€ 18.16.23.png

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

                                  Well I can not duplicate that.. So I again turned on just normal forwarding, no dot. No dnssec

                                  You can see when I first query there is response time, then if query again response is zero -- because its cached.

                                  cantdup.png

                                  Asking unbound shouldn't have any signification additional latency.. Sure there could be few ms, and there is going to be deviation for any specific 1 off query, etc. But maybe when unbound asked whoever there was a delay in that response.

                                  I suggest you sniff, and up your logging level.. And do more than just query of 1 fqdn.. Your going to have to do more testing to show that unbound is adding latency to that extent.. I think your seeing outlayers, or do not have a full picture of what is happening during the 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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