Issue: if you are receiving the several instances of the following error in WHM while deleting the nameserver entry from the option >> Nameserver IPs
“Sorry, the nameserver ip a.b.c.d cannot be removing since it is still registered with an ICANN register.”
Following resolution will be helpful to you:
This is caused by WHM doing whois lookups to determine if the nameservers are registered or not.
To correct the issue, go to WHM >> Server Configuration -> Tweak Settings and check the box labeled “Disable whois lookups for the nameserver ip manager.”.
Save the changes and you should be able to remove the nameserver now.
Or edit the file from the shell
# vi /etc/nameserverips
And delete those entries.
Thats it 🙂