| step | query | auth | servers |
| 1 | 21.110.216.15.in-addr.arpa. | . | (i,d,m,a,f,h,l,k,b,e,g,c,j).root-servers.net. |
| 2 | 21.110.216.15.in-addr.arpa. | in-addr.arpa. | (e,b,c,d,a,f).in-addr-servers.arpa. |
| 3 | 21.110.216.15.in-addr.arpa. | 15.in-addr.arpa. | (ns5,ns6,ns1,ns4,ns2,ns3).hp.net. |
We pick