What happens when one out of three NSs are down?

[Dave Sparro]

On 6/11/2013 7:12 PM, Gary Wallis wrote:
>
> What really happens in the real world when 1 out of three 
> authoritative NSs are down for 30 minutes due to a datacenter outage?
>
> For example, we have 3 NSs:
>
> ns1.someisp.net 12.23.34.45
> ns2.someisp.net 23.34.45.56
> ns3.someisp.net 34.45.56.67
>
> All in different datacenters.
> All are authoritative for a given zone.
> All have the same zone data and SOA serial number for the zone. 

Do the NS records (and corresponding A records) in the zone data match 
the records that are stated above?

Do the NS (and any corresponding glue) records that have been added to 
the TLD/root servers match the records as well?