Question about connections to BIND and tcp 443

[Jan-Piet Mens]

> They are currently being block from connecting to 443 since these
> servers are only DNS. Is there any reason for clients to connect to
> tcp 443 for any type of DNS resolution?

Sounds a bit as though your clients think the BIND box is a HTTP origin
server... I'd look into what programs they're running and how those are
configured. Other than that, no: there is no reason for a typical DNS
client to attempt TCP/443 unless your clients are running dnssec-trigger
[1]

        -JP

[1] http://www.nlnetlabs.nl/projects/dnssec-trigger/