Hi,
I have a client wanting to change the nameservers of their .de domain. They received this message from their current hosting provider:

The domain

xxxxxxxx.de

has NOT been updated.
The following errors were detected:
== SERVER ns2.zopiwebhosting.com. ==
no IP number set
no IP number set
ns2.zopiwebhosting.com.: NOT AUTHORITATIVE for the zone xxxxxxx.de
== END ==
There is a SPOF - single point of failure - in NS-set!

This happens if all NS-RR for a domain are in the same subnet.
Server ns2.zopiwebhosting.com. is not authoritative!

I have marked out their domain name to protect privacy. Can anyone tell me what this means and how I can fix this?

Thanks

I have resolved this issue. Thanks anyway.