I observe at least three installations of different Linux (Ubuntu 16.04, Antergos latest as per 2017-06-28, Debian 9.0) with the following behaviour:
- IPv6 is deconfigured (no Address assigned)
- The DNS server receives simultaneous A and AAAA queries for any resoultion to be performed.
I already messed around with
resolv.conf (non-existing option
gai.conf, without any success.
The C program I took from this website does not perform AAAA queries.
This simple and stupid PHP program does perform both, AAAA and A DNS queries, simultaneously:
<?php $ch = curl_init($argv); curl_exec($ch);
Since there may be dozens of clients (also within LXC containers) having this issue by throwing useless queries at the DNS server, I want to ask if there is a way to prevent AAAA DNS queries by these standard system calls (
getaddrinfo and the like).
Note that these AAAA queries are performed via IPv4, since the clients and also the DNS server do not have IPv6 configured:
$ ip addr show dev venet0 2: venet0: <BROADCAST,POINTOPOINT,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN link/void inet 127.0.0.2/32 scope host venet0 inet 192.168.8.40/32 brd 192.168.8.40 scope global venet0:0