On Tue, 25 Jul 2017, Torbjorn Pettersson wrote: > Same result regardless of how many times I run it. Great, > but telnet, however, chooses one of the a records at "random".
DNS sortlist works mostly for apps using outdated APIs. telnet in stretch has long moved to the new APIs that are IPv6-enabled properly, and therefore they will use *all* A and AAAA records returned from the DNS lookup (so *dns* sort order doesn't matter since it will consider every result regardless of the order) and select which ones to try first based on several hardcoded rules *and* (in glibc's case) local configuration related to IPv6+IPv4 source address selection. Please configure your network preference ordering in /etc/gai.conf, and it should work for the majority of the stuff in Debian. In fact, you can even configure ipv4 ranges (or all of it) to be prefered over some ipv6 ranges (or all of it), etc. -- Henrique Holschuh