Diagnostic help part 2

[Doug Barton]

On 10/1/14 8:17 AM, Barry Margolin wrote:
> In article <mailman.1035.1412133286.26362.bind-users at lists.isc.org>,
>   Eli Heady <eli.heady at gmail.com> wrote:
>
>> With response sizes growing (dnssec, ipv6), answers are more likely to be
>> too large for UDP.
>
> That's unlikely. That's why EDNS was created, so that these large
> answers wouldn't require TCP.

... and more than a decade later EDNS still fails very often due to 
misconfigured and/or ancient firewalls that don't understand it. 53/TCP 
is part of the spec, and should not be blocked.

Doug