On Thu, 21 Apr 2016, Trevor Cordes wrote: > The problem: IPv6! Argh! > Is there a firewall blocking *TCP* port 53? With DNSSEC and IPv6 we will see more DNS responses that are too big to send over UDP. Ref: http://serverfault.com/questions/404840/when-do-dns-queries-use-tcp-instead-of-udp Regards, Daryl