DNS server does not resolve its own NS hostnames (ns1/ns2)

[cofyc]

Problem

When the domain is configured with proper NS delegation using in-domain nameservers (e.g., ns1.anyip.dev, ns2.anyip.dev), the anyip DNS server does not return A records for these NS hostnames. This causes recursive resolvers to fail when following the delegation chain.

Steps to Reproduce

1. Configure glue records at the TLD registrar:

   anyip.dev.     NS    ns1.anyip.dev.
   anyip.dev.     NS    ns2.anyip.dev.
   ns1.anyip.dev. A     203.0.113.10
   ns2.anyip.dev. A     203.0.113.10
   

2. Query the TLD directly -- glue records are present:

   $ dig NS anyip.dev @ns-tld1.charlestonroadregistry.com. +norecurse +additional
   ;; AUTHORITY SECTION:
   anyip.dev.       10800  IN  NS  ns1.anyip.dev.
   anyip.dev.       10800  IN  NS  ns2.anyip.dev.
   
   ;; ADDITIONAL SECTION:
   ns1.anyip.dev.   3600   IN  A   203.0.113.10
   ns2.anyip.dev.   3600   IN  A   203.0.113.10
   

3. Query the anyip server directly for ns1/ns2:

   $ dig A ns1.anyip.dev @203.0.113.10
   ;; ANSWER SECTION:
   (empty)
   
   $ dig A ns2.anyip.dev @203.0.113.10
   ;; ANSWER SECTION:
   (empty)
   

4. Full trace fails:

   $ dig NS anyip.dev +trace
   anyip.dev.  10800  IN  NS  ns1.anyip.dev.
   anyip.dev.  10800  IN  NS  ns2.anyip.dev.
   couldn't get address for 'ns1.anyip.dev': not found
   couldn't get address for 'ns2.anyip.dev': not found
   

Expected Behavior

The DNS server should return A records for its own NS hostnames:

$ dig A ns1.anyip.dev @203.0.113.10
ns1.anyip.dev.  259200  IN  A  203.0.113.10

$ dig A ns2.anyip.dev @203.0.113.10
ns2.anyip.dev.  259200  IN  A  203.0.113.10