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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">Hi Frank,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">thanks for your fast response. The thing with the „whitelist“-pool works like charm – thanks for this
</span><span style="font-size:11.0pt;font-family:Wingdings;color:#1F497D;mso-fareast-language:EN-US">J</span><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">For my both existing rules, the regex has the behavior, that queries for „*.subdomain.example.org“ should be blocked, but „subdomain.example.org“
itself is an existing domain and should be handled normally. Background: we had an big amount of queries „testing“ massively all possible (and impossible) (sub)-subdomains for this subdomain. That is why we first came up with the idea of using dnsdist to relax
the load on our powernds-Servers (they went nearly down) </span><span style="font-size:11.0pt;font-family:Wingdings;color:#1F497D;mso-fareast-language:EN-US">J</span><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">Best regards,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">Markus<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">Von:</span></b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"> dnsdist <dnsdist-bounces@mailman.powerdns.com>
<b>Im Auftrag von </b>Frank Louwers via dnsdist<br>
<b>Gesendet:</b> Freitag, 13. November 2020 11:45<br>
<b>An:</b> dnsdist@mailman.powerdns.com<br>
<b>Betreff:</b> Re: [dnsdist] Regex-Question<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Hi Markus,<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">On Nov 13, 2020, at 11:33 AM, Markus Ehrlicher via dnsdist <<a href="mailto:dnsdist@mailman.powerdns.com">dnsdist@mailman.powerdns.com</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">Hello together,<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"> <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">I have dnsdist in Version 1.5.1 installed and are successfully using some rules for blocking/slowing down queries for some subdomains:<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"> <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">addAction(RegexRule(".*\\.subdomain\\.example\\.org$"), ERCodeAction(DNSRCode.SERVFAIL))<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">addAction(RegexRule(".*\\.?example\\.org$"), QPSAction(10))<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">You don't need to use a RegexRule, you can just do something like this:<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">addAction("<a href="http://subdomain.example.org">subdomain.example.org</a> ", DropAction()) (or whatever other action you want to do).<o:p></o:p></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"> <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">But now, I have a little more complicated task: I want to block all queries for *.<a href="http://example.org/"><span style="color:#954F72">example.org</span></a>, except<span class="apple-converted-space"> </span><a href="http://subdomain1.example.org/"><span style="color:#954F72">subdomain1.example.org</span></a><span class="apple-converted-space"> </span>and<span class="apple-converted-space"> </span><a href="http://subdomain2.example.org/"><span style="color:#954F72">subdomain2.example.org</span></a>.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">I tried it with some Online Regex-Tools (<a href="https://regex101.com/r/Y2sXP8/3"><span style="color:#954F72">https://regex101.com/r/Y2sXP8/3</span></a>), but these rule is
not accepted by dnsdist. I know that the incasesensitive-flag isn’t needed in dnsdist, but this was for testing. Is there a good documentation about the regex escpecially for dnsdist or is my problem not solvable with dnsdist regex?<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"> <o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">The first action that matches, will be executed. So if you first add the domains that should get trough (assign them to a pool for instance), then then the action that should block / servfail / tc=1 / rate limit. / .... you should be fine.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Kind Regards,<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Frank Louwers<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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