<div dir="ltr"><div>
<span class="gmail-im">> my question is why would anyone do this, as this apparently does not make<br>
> sense.</span> <br></div><div><br></div><div>
<span class="gmail-tlid-translation gmail-translation" lang="en"><span title="" class="gmail-">Because when I was from a server that was querying the reverse record 250.199.212.125.in-addr.arpa it gave an error with the "SERVFAIL" error code so I tried to query directly to the hosting that managed it to determine the cause.</span></span>
</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">Vào Th 4, 19 thg 8, 2020 vào lúc 22:00 Mark Andrews <<a href="mailto:marka@isc.org">marka@isc.org</a>> đã viết:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><br>
<br>
> On 20 Aug 2020, at 00:41, Matus UHLAR - fantomas <<a href="mailto:uhlar@fantomas.sk" target="_blank">uhlar@fantomas.sk</a>> wrote:<br>
> <br>
>> On Wed, Aug 19, 2020 at 7:42 AM Matus UHLAR - fantomas<br>
>> <<a href="mailto:uhlar@fantomas.sk" target="_blank">uhlar@fantomas.sk</a>> wrote:<br>
>>> again, why you query for 250.0-24.199.212.125.in-addr.arpa<br>
>>> under normal circumstances there's no point of querying that name.<br>
> <br>
> On 19.08.20 10:05, tale via bind-users wrote:<br>
>> Well yes and no. While an individual user would typically not,<br>
>> resolvers sure will. While trying to resolve<br>
>> 250.199.212.125.in-addr.arpa, it will eventually get to<br>
>> 250.199.212.125.in-addr.arpa CNAME 250.0-24.199.212.125.in-addr.arpa.<br>
> <br>
> my question is why would anyone do this, as this apparently does not make<br>
> sense.<br>
<br>
Presumably because they don’t know that APNIC can delegate the /24s that make<br>
up the /17 independently of each other.<br>
<br>
> someone (vietel) illogically delegated whole /24 subnet to broken servers:<br>
> <br>
> 199.212.125.in-addr.arpa. 86400 IN NS <a href="http://dns2.vietel.com.vn" rel="noreferrer" target="_blank">dns2.vietel.com.vn</a>.<br>
> 199.212.125.in-addr.arpa. 86400 IN NS <a href="http://dns1.vietel.com.vn" rel="noreferrer" target="_blank">dns1.vietel.com.vn</a>.<br>
> <br>
> 0.199.212.125.in-addr.arpa has address 125.235.4.59<br>
> 1.199.212.125.in-addr.arpa is an alias for 1.0-24.199.212.125.in-addr.arpa.<br>
> ...<br>
> 255.199.212.125.in-addr.arpa is an alias for 255.0-24.199.212.125.in-addr.arpa.<br>
> <br>
> <br>
>> Then it will need to resolve the canonical name, and a response like<br>
>> the original one that was shown will be clearly buggy.<br>
>> <br>
>> I say "possibly" because from my vantage, all three of<br>
>> ns{,1,2}.<a href="http://viettelidc.com.vn" rel="noreferrer" target="_blank">viettelidc.com.vn</a>, the authorities for<br>
>> 0-24.199.212.125.in-addr.arpa, are giving fine answers right now (on<br>
>> udp; blocked on tcp). This includes the originally reported problem<br>
>> IP, 115.84.177.8<br>
> <br>
> <br>
> <br>
> -- <br>
> Matus UHLAR - fantomas, <a href="mailto:uhlar@fantomas.sk" target="_blank">uhlar@fantomas.sk</a> ; <a href="http://www.fantomas.sk/" rel="noreferrer" target="_blank">http://www.fantomas.sk/</a><br>
> Warning: I wish NOT to receive e-mail advertising to this address.<br>
> Varovanie: na tuto adresu chcem NEDOSTAVAT akukolvek reklamnu postu.<br>
> Fucking windows! Bring Bill Gates! (Southpark the movie)<br>
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</blockquote></div>