for www.lycos.com. Once it has the IP address it can connect and download the WWW pages.The process of taking a hostname and finding the IP address is called name resolution.B) Methods Of Name ResolutionThere are two methods that can be used to perform name resolutionthe /etc/hosts file, andthe Domain Name Service.4.14 /etc/hostsA) /etc/hostsOne way of performing name resolution is to maintain a file that contains a list of hostnames and their equivalent IP addresses. Then when you want to know a machine's IP address you look up the file.Under UNIX the file is /etc/hosts. /etc/hosts is a text file with one line per host. Each line has the formatIP_address hostname aliasesComments can be indicated by using the hash # symbol. Aliases are used to indicate shorter names or other names used to refer to the same host.For example , the hosts file of the machine aldur looks like this ;# every machine has the localhost entry127.0.0.1 localhost loopback138.77.36.29 aldur.cqu.edu.au aldur138.77.1.1 jasper.cqu.edu.au jasper138.77.37.28 pol.cqu.edu.au pol4.15 DOMAIN NAME SERVİCEA) Domain Name Service (DNS)The following reading on the DNS was taken from http://www.aunic.net/dns.htmlIn the early days of the Internet, all host names and their associated IP addresses were recorded in a single file called hosts.txt, maintained by the Network Information Centre in the USA. Not surprisingly, as the Internet grew so did this file, and by the mid-80's it had become impractically large to distribute to all systems over the network, and impossible to keep up to date. The Internet Domain Name System (DNS) was developed as a distributed database to solve this problem. It's primary goal is to allow the allocation of host names to be distributed amongst multiple naming authorities, rather than centralised at a single point.B) DNS StructureThe DNS is arranged as a hierarchy, both from the perspective of the structure of the names ...
