Public bug reported: The pdns-recursor in Xenial returns this:
$ dig A umcg-nl.mail.protection.outlook.com. @127.0.0.1 +edns +dnssec ... ;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 57895 While it should return this: ... umcg-nl.mail.protection.outlook.com. 10 IN A 213.199.154.87 umcg-nl.mail.protection.outlook.com. 10 IN A 213.199.154.23 Because the relevant NS returns FORMERR (it doesn't support EDNS): $ dig A umcg-nl.mail.protection.outlook.com. \ @ns1-proddns.glbdns.o365filtering.com. +edns +dnssec ... ;; ->>HEADER<<- opcode: QUERY, status: FORMERR, id: 1004 ... ;; WARNING: EDNS query returned status FORMERR - retry with '+nodnssec +noedns' This has been fixed in later versions of pdns, specifically here: https://github.com/PowerDNS/pdns/commit/9d534f2a12defc44d2a79291bf34b82e5ee28121 After applying that patch onto 4.0.0~alpha2-2, pdns-recursor behaves as expected and returns the correct A records. This bug manifested itself in our case through Postfix not being able to send mail to Office 365 domains. When postfix tried to enable optional DNSSEC validation -- which it did because of a builtin default -- the A record lookups would start to fail, and this failure would be cached for non-EDNS lookups as well. See original discussion here: http://postfix.1071664.n5.nabble.com/EDNS-DANE-trouble-with-Microsoft-mail-protection-outlook-com-td87331.html#a87353 "EDNS / DANE trouble with Microsoft mail.protection.outlook.com." Attached, the patch that appears to fix the problem. IMHO, Xenial (being an LTS) needs to get this fixed. Either by updating from 4.0.0 to something more recent, or by applying this patch. Cheers, Walter Doekes OSSO B.V. ** Affects: pdns-recursor (Ubuntu) Importance: Undecided Status: New ** Tags: patch ** Patch added: "9d534f2a12defc44d2a79291bf34b82e5ee28121.patch" https://bugs.launchpad.net/bugs/1646538/+attachment/4785809/+files/9d534f2a12defc44d2a79291bf34b82e5ee28121.patch -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1646538 Title: pdns-recursor 4.0.0~alpha2-2 fails on FORMERR response to EDNS query To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/pdns-recursor/+bug/1646538/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs