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    IPv6 and DNS Lead to Some Slow Websites

    Scheduled Pinned Locked Moved IPv6
    20 Posts 4 Posters 2.8k Views
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    • B
      bfeitell
      last edited by

      What are your settings in DNS Resolver?

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      • W
        wre136
        last edited by

        Any easy way to get that other than a screen shot?

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        • PippinP
          Pippin
          last edited by

          ICMP blocked somewhere?
          Maybe Prefer IPv4 over IPv6 helps?

          I gloomily came to the ironic conclusion that if you take a highly intelligent person and give them the best possible, elite education, then you will most likely wind up with an academic who is completely impervious to reality.
          Halton Arp

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          • B
            bfeitell
            last edited by bfeitell

            You should leave the WAN MTU at the default. Being able to send a max ping of 1472 shows that 1500 is your actual MTU on the connection. The missing 8 bytes are the ICMP header for the ping packets. Please report what you have set for "IP Do-Not-Fragment compatibility", in system/advanced/firewall&nat?

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            • W
              wre136 @Pippin
              last edited by

              @pippin Under system i did specify for it to use IPv4 over IPv6 but sadly didn't change anything

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              • B
                bfeitell
                last edited by

                A screenshot of the first settings page would be perfect.

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                • W
                  wre136 @bfeitell
                  last edited by

                  @bfeitell I have the IP Don-Not-Fragment compatibility flag not set. Should I enable that feature?

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                  • B
                    bfeitell
                    last edited by bfeitell

                    I would try it, and see if it has an effect on the function of DNS Resolver. I think that playing with your MTU on the WAN might be the cause, but I'd still like to see your settings for DNS Resolver. If you are using dns over tls with the Quad9 resolvers, that might explain things. I have found the Quad9 resolvers to be very slow in comparison to the cloudflare resolvers.

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                    • W
                      wre136
                      last edited by

                      Below are the basic settings I have for DNS Resolver:

                      0_1538518269334_DNS Resolver Settings.png

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                      • B
                        bfeitell
                        last edited by

                        Check the log file for DNSBL in pfblocker. Depending upon what lists you are using, you might be blocking access to certain name servers you need for DNS Resolver to work correctly. If you temporarily disable pfb_dnsbl, you will need to reload on the update page to clear any blocks. Then test the DNS Resolver again.

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                        • W
                          wre136
                          last edited by

                          Pfblockerng isn't much of the issue. I factory reset my router and did a minimal setup using DNS Resolver and no pfblockerng. Still had the same issue. After seeing no change, I restored my original config bringing pfblockerng back

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                          • sigiS
                            sigi @wre136
                            last edited by

                            @wre136 I bet on https://redmine.pfsense.org/issues/8934 have own DNS on FreeBSD and get many problems with IPv6 DNS and Fragments. Disabling scrubbing helps. But then IPv4 DNS has same problems :-(

                            Oct  9 17:25:41 host1 kernel: ipfw: 65300 Deny TCP [2001:500:e::1] [2axx:xxxx:xxxx:xxxx::53] in via bge0 (frag 1217fb81:188@9856)
Oct  9 17:25:57 host1 kernel: ipfw: 65300 Deny TCP [2001:500:f::1] [2axx:xxxx:xxxx:xxxx::53] in via bge0 (frag 4d6091d8:188@9856)
Oct  9 17:26:45 host1 kernel: ipfw: 65300 Deny TCP [2001:500:e::1] [2axx:xxxx:xxxx:xxxx::53] in via bge0 (frag 350be3db:188@9856)
Oct  9 17:31:29 host1 kernel: ipfw: 65300 Deny UDP [2001:500:40::1] [2axx:xxxx:xxxx:xxxx::53] in via bge0 (frag b576286c:361@9856)
Oct  9 17:51:24 host1 kernel: ipfw: 65300 Deny UDP [2001:470:1a::1] [2axx:xxxx:xxxx:xxxx::53] in via bge0 (frag 8533c2a5:642@9856)
Oct  9 17:51:26 host1 kernel: ipfw: 65300 Deny UDP [2001:5a0:10::1] [2axx:xxxx:xxxx:xxxx::53] in via bge0 (frag e06893c2:650@9856)
Oct  9 17:53:07 host1 kernel: ipfw: 65300 Deny UDP [2001:67c:18c4:2000::11:53] [2axx:xxxx:xxxx:xxxx::53] in via bge0 (frag 55df3089:362@9856)
Oct  9 18:11:05 host1 kernel: ipfw: 65300 Deny UDP [2001:500:48::1] [2axx:xxxx:xxxx:xxxx::53] in via bge0 (frag 8424932b:361@9856)
Oct  9 18:11:25 host1 kernel: ipfw: 65300 Deny UDP [2001:500:b::1] [2axx:xxxx:xxxx:xxxx::53] in via bge0 (frag 9da68734:361@9856)
Oct  9 18:14:41 host1 kernel: ipfw: 65300 Deny UDP [2001:500:c::1] [2axx:xxxx:xxxx:xxxx::53] in via bge0 (frag 69a41126:361@9856)
Oct  9 18:18:05 host1 kernel: ipfw: 65300 Deny UDP [2001:500:40::1] [2axx:xxxx:xxxx:xxxx::53] in via bge0 (frag a639e4fd:361@9856)
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