First you should check which nameserver is responding for this tld. For example if we wanna check .com domain we need to ask proper nameserver

dig +short com. NS
e.gtld-servers.net.
k.gtld-servers.net.
j.gtld-servers.net.
h.gtld-servers.net.
m.gtld-servers.net.
a.gtld-servers.net.
l.gtld-servers.net.
i.gtld-servers.net.
g.gtld-servers.net.
c.gtld-servers.net.
d.gtld-servers.net.
f.gtld-servers.net.
b.gtld-servers.net.

We can chose some random dns server from them and execute

dig +norec @b.gtld-servers.net. example.com. NS

Then we will get which nameservers on which ip are responding for this domain

Материалът Debugging dns glue records е публикуван за пръв път на rosen4o.net.