delegation NS records

[Niall O'Reilly]

On 14 Jul 2017, at 14:07, bind at zq3q.org wrote:

> only a single **delegation** NS record
>     needed

Actually, there should be two or more, and their IP addresses
should belong to different networks.

RFC1034, section 4.1:

A given zone will be available from several name servers to insure its
availability in spite of host or communication link failure.  By
administrative fiat, we require every zone to be available on at least
two servers, and many zones have more redundancy than that.

/Niall