I think I got bit yesterday by the above... I was noticing terrible resolution speed, so checked messages (btw, "service bind9 status" provides brief, but decent-ish characterization of things), and noticed many messages indicating failing resolutions against IPv6 addresses. There is a common pair of bits of Bind configuration: a) One might set options to prefer not to use IPv6 addresses, so in /etc/bind/named.conf.options, change listen-on-v6 { all;}; to listen-on-v6 { none; }; b) This was where SystemD got into the mix... Pass the "-4" option when running named to use only IPv4. This seems to be the highly significant bit. On Debian-derived systems, the usual recipe is to add "-4" to /etc/defaults/bind --> OPTIONS="-4" However, the SystemD config for Bind9 lives in /lib/systemd/system/bind9.service, and apparently there is recent change there that that configuration no longer reads from /etc/defaults/bind, so that to have named get the "-4" option requires altering /lib/systemd/system/bind9.service. Seems like it needs to be altered directly. This isn't necessarily a "SystemD bug", rather a packaging bug in Debian. It still was fairly annoying. I have yet to report it properly, probably deserves a bit more research, in case my diagnosis is off a bit. -- When confronted by a difficult problem, solve it by reducing it to the question, "How would the Lone Ranger handle this?"