Alternatively, there might be workarounds e.g. listing
a slightly
different dns name in the short-term e.g. sub1 or top1 in both DNS and
delegation and changing it back a bit later.
This is what I am going to try next.
Whilst it was some time ago, I do seem to recall I once had to do this in
similar circumstances with 123-reg. It seemed that if you were merely
changing the IP address of a glue record then their system did not detect
the change hence nothing was done. Instead I had to temporarily remove the
delegation with the (old) glue record, let that ripple through, and then
add it back in with the new IP address. It didn't affect resolution in the
interim given I had the second authoritative nameserver still being
referenced.
First go and the Nominet computer says:
Name servers:
ns1.example.co.uk 85.119.83.xx
ns2.example.co.uk 212.13.195.yy
Argh!
Second go, with two names that definitely had not been used ever before:
Name servers:
ffs.example.co.uk 85.119.83.xx
wtf.example.co.uk 85.119.83.yy
Finally...
Ian