rnet address of www.icann.org, your computer must first find the .org registry database. The TLD name server tells the local server which primary name server and secondary name server are authoritative for the domain in the requested URL (icann.org in our example). The local name server can then contact the domain's primary name server to resolve the full name of the host in the URL (www.icann.org in our example). If the primary name server does not respond, the local name server contacts the secondary name server. One of those name servers will have the proper information, and it will then pass that information back to the local name server. The local name server sends the information back to your browser, which then uses the IP address to contact the proper site. Top-Level Domains For some time, there have been seven generic TLDs (gTLDs): commercial government military Chapter 8 The Internet and IP Infrastructures education for network operation nonprofit organizations international treaty organizations gTLDs are unrestricted; this means anyone from anywhere can register as many of these domain names as they like. In addition, 11 TLDs have been added since 2001: .aero air-transport industry .arpa infrastructure businesses .coop cooperatives any use related to jobs .museum museums .name individuals accountants, lawyers, and physicians .root infrastructure .travel travel-related sites A few more TLDs are in the startup phase, including .cat, mobi, post, and .tel. In addition, some new TLDs have been proposed, including .asia, .geo, kid, .mail, .SCO, web, and .XXX. The .nato TLD has been retired, and .example, invalid, .localhost, and .test are held in reserve at this time. There are also country code TLDs (ccTLDs). Each of these is a two-letter coun- try code (e.g., .au, .ca), and there are 250 ccTLDs, including a .us domain for the United States. If you wanted to protect your domain name in the .com domain, for example, you would actually have to register it in 251 domains-.com and then .com with the appropriate