1. A, B, C, D. The DNS namespace includes root domains, top-level domains, second-level domains, and host names. You can even have additional subdomains at levels beneath the second level. However, NetBIOS names are not a component of the DNS namespace.
2. C, D, F. These three computer names qualify as FQDNs, which generally consist of a host name, second-level domain name, and top-level domain name separated by periods. SERVER1 is a NetBIOS name, not a FQDN. http://www is an incomplete name; further, a FQDN does not start with http:. webserver.anydomain. is an incomplete name.
3. C. In an iterative query, the name is resolved in the sequence root domain, top-level domain, second-level domain, and then host name. If the ISP’s DNS server ...