At the moment, AWS's provided DNS servers and Route53 appear to always match the question case in the answer. (As do Google's DNS servers)
Bind seems to be the odd man out in not doing that by default. On Thu, Apr 12, 2018 at 7:08 AM, Jim Freeman <sovr...@gmail.com> wrote: > It will be important to know which behavior AWS's Route53/DNS servers use ? > > Using stock Debian/Stretch BIND9 (1:9.10.3.dfsg.P4-12.3+deb9u4), we see > haproxy downing backend servers with > "Server<foo> is going DOWN for maintenance (unspecified DNS error)." > https://github.com/haproxy/haproxy/search?q=unspecified+dns+error > > We're expecting/testing to see if bind9's "no-case-compress { any; }" > directive > addresses this, but many folks do not control their DNS services (and as > requisite > AWS/Route53 capabilities mature, neither will we). > > > On Tue, Apr 10, 2018 at 3:11 PM, Ben Draut <dra...@gmail.com> wrote: > >> It's interesting that the default behavior of HAProxy resolvers can >> conflict with the default behavior of bind. (If you're unlucky with >> whatever bind has cached) >> >> By default, bind uses case-insensitive compression, which can cause it to >> use a different case in the ANSWER than in the QUESTION. (See >> 'no-case-compress': https://ftp.isc.org/isc/bind9/cur/9.9/do >> c/arm/Bv9ARM.ch06.html) We were impacted by this recently. >> >> Also interesting: https://indico.dns-oarc.net/event/20/session/2/ >> contribution/12/material/slides/0.pdf >> >> >> On Mon, Apr 9, 2018 at 2:12 AM, Baptiste <bed...@gmail.com> wrote: >> >>> So, it seems that responses that does not match the case should be >>> dropped: >>> https://twitter.com/PowerDNS_Bert/status/983254222694240257 >>> >>> Baptiste >>> >> >> >
