Re: DNS resolver and mixed case responses

Hi all, Thanks a lot for your various investigations! As a conclusion, HAProxy's behavior is "as expected". Baptiste

Re: DNS resolver and mixed case responses

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 wrote: > It will be

Re: DNS resolver and mixed case responses

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 is going DOWN for maintenance (unspecified DNS error)."

Re: DNS resolver and mixed case responses

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

Re: DNS resolver and mixed case responses

So, it seems that responses that does not match the case should be dropped: https://twitter.com/PowerDNS_Bert/status/983254222694240257 Baptiste

Re: DNS resolver and mixed case responses

On Fri, Apr 6, 2018 at 11:10 AM, Dennis Jacobfeuerborn < denni...@conversis.de> wrote: > On 04.04.2018 16:30, Tim Düsterhus wrote: > > Dale, > > > > Am 03.04.2018 um 16:17 schrieb Dale Smith: > >> I'm trying to understand what system is at fault here; the DNS server > for > >> not responding with

Re: DNS resolver and mixed case responses

On 04.04.2018 16:30, Tim Düsterhus wrote: > Dale, > > Am 03.04.2018 um 16:17 schrieb Dale Smith: >> I'm trying to understand what system is at fault here; the DNS server for >> not responding with the same case as the query, or HAProxy which >> should be >> performing a case insensitive match. >

Re: DNS resolver and mixed case responses

Dale, Am 03.04.2018 um 16:17 schrieb Dale Smith: I'm trying to understand what system is at fault here; the DNS server for not responding with the same case as the query, or HAProxy which should be performing a case insensitive match. This is left unspecified in the standards, but on the

Re: DNS resolver and mixed case responses

On Tue, 3 Apr 2018 at 17:35 Baptiste wrote: > > Hi Dale, > > Thanks for the report! > Please share your patch here and I'll have a look, so we could merge it. > > Baptiste > Hi Baptiste, I've attached a patch file for haproxy-1.7 that performs the case insensitive match

Re: DNS resolver and mixed case responses

On Tue, Apr 3, 2018 at 4:17 PM, Dale Smith wrote: > Hello All, > > I have noticed a potential issue in HAProxy 1.7 where a backend server has > reported in logs an 'unspecified DNS error' and been marked down for > maintenance. > > After some investigation, I have found that

DNS resolver and mixed case responses

Hello All, I have noticed a potential issue in HAProxy 1.7 where a backend server has reported in logs an 'unspecified DNS error' and been marked down for maintenance. After some investigation, I have found that our internal DNS server is responding with non-lowercase domain names in the Answer