currently, on https://my-miab.com/admin#
The language reads:
Using a secondary nameserver
If your TLD requires you to have two separate nameservers, you can either set up external DNS and ignore the DNS server on this box entirely, or use the DNS server on this box but add a secondary (aka “slave”) nameserver.
If you choose to use a secondary nameserver, you must find a secondary nameserver service provider. Your domain name registrar or virtual cloud provider may provide this service for you. Once you set up the secondary nameserver service, enter the hostname (not the IP address) of their secondary nameserver in the box below.
xfr:18.104.22.168 uz52...9.free.ns.buddyns.com [and 2 more buddies here]
Multiple secondary servers can be separated with commas or spaces (i.e.,
ns2.hostingcompany.com ns3.hostingcompany.com ). To enable zone transfers to additional servers without listing them as secondary nameservers, add
Clear the input field above and click Update to use this machine itself as secondary DNS, which is the default/normal setup.
since it may not be intuitively clear, I suggest adding this text at the end:
If you clear the input field from those secondary nameservers, they will no longer be announced via NS-records and no longer be used by MiaB, effective immediately.
Some people might think that those added 2ndaries remain active even with that Input Line emptied.
xfr:22.214.171.124 allows you to do a quick AXFR to this webDig tool: web dig DNS query tool