We pick f.root-servers.net, one of the 13 root servers (1), and ask it about d0.cctld.afilias-nst.org and learn that org is delegated to six name servers (2), so we ask d0.org.afilias-nst.org where we learn that afilias-nst.org is delegated to four name servers, including ns1.ams1.afilias-nst.info (3), so we ask that one and learn that cctld.afilias-nst.org is delegated to four name servers (4), so we ask b0.cctld.afilias-nst.org and get the following answer: