We pick g.root-servers.net, one of the 13 root servers (1), and ask it about 1.60.254.199.in-addr.arpa and learn that in-addr.arpa is delegated to six name servers (2), so we ask d.in-addr-servers.arpa where we learn that 60.254.199.in-addr.arpa is delegated to five name servers, including ns1.ams1.afilias-nst.info (3), so we ask that one and get the following answer: