| Name | Parent zone | Child zone | Authoritative IPs |
| Exists? | Glue/additional records | Exists? |
| lhcns1.nlm.nih.gov | indeterminate* | yes | A | 130.14.55.72 |
| AAAA | 2607:f220:41e:7055::72 |
| lhcns2.nlm.nih.gov | indeterminate* | yes | A | 130.14.55.128 |
| AAAA | 2607:f220:41e:7055::128 |
| dns1-ncbi.ncbi.nlm.nih.gov | indeterminate* | yes | A | 130.14.29.31 |
| AAAA | 2607:f220:41e:4290::31 |
| dns2-ncbi.ncbi.nlm.nih.gov | indeterminate* | yes | A | 130.14.29.32 |
| AAAA | 2607:f220:41e:4290::32 |
| ns.nih.gov | indeterminate* | yes | A | 128.231.128.251 |
| AAAA | 2607:f220:404:101::80e7:80fb |
| ns2.nih.gov | indeterminate* | yes | A | 128.231.64.1 |
| AAAA | 2607:f220:418:4101::80e7:401 |
| ns3.nih.gov | indeterminate* | yes | A | 165.112.4.230 |
| AAAA | 2607:f220:402:1801::a570:4e6 |