We pick j.root-servers.net, one of the 13 root servers (1), and ask it about ibmwr.org and learn that org is delegated to six name servers (2), so we ask b0.org.afilias-nst.org where we learn that ibmwr.org is delegated to five name servers, including dns4.pageplanet.com (3), so we ask that one and get the following answer: