It seems that PowerDNS‘s pdns_recursor crashes on FreeBSD under load.
I’ve replaced it by a bind recursor. Excerpt from named.conf:
options {
directory "/etc/namedb";
pid-file "/var/run/named/pid";
dump-file "/var/dump/named_dump.db";
statistics-file "/var/stats/named.stats";
listen-on port XXXX { 127.0.0.1; };
};
zone "." {
type hint;
file "named.root";
};