Adrian Ulrich wrote:
Hi Jeroen
;; ->>HEADER<<- opcode: QUERY, status: REFUSED, id: 22394 ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0
We are aware that ns.bwlbmsg1zhh.bluewin.ch. doesn't play well with IPv6 (and we also know that some lb-vendors are not able to fix such simple bugs).
And tada, my sweet postfix/bind/powerdns combo will give up on it as there is clearly no answer to be gotten for that hostlabel.
ulrich@fuzzy:~$ dnsmx bluewin.ch 10 mxbw.bluewin.ch <-- ns.bwlbmsg1zh[hb].bluewin.ch 42 mxzhh.bluewin.ch <-- dns[1234].bluewin.ch 42 mxzhb.bluewin.ch <-- dns[1234].bluewin.ch 66 mx49.bluewin.ch <-- dns[1234].bluewin.ch
Why doesn't your postfix/bind/powerdns combo use mxzhb/mxzhh ?
It does, but it does give up on the mxbw one.
The reason that I noticed is that for signup we do an MX check, to check if they are setup correctly, bluewin.ch failed the test with flying smudged colors... It is on the whitelist now though, but before that it was nicely rejecting any signup attempt from people using that as an email address. It also doesn't leave a good impression on customers I guess that the ISP can't even have a proper email setup.
Nevertheless, I would gently try and suggest to fix it for real instead of letting it run like this. Of course that is easier said than done, especially with a magic blackbox which is broken which resides in your network...
Greets, Jeroen