Numbers and Names (primer)

Internet Addresses | Numbers and Names

Numbers and Names

The address on a normal letter typically has several lines, each of which supplies different levels of information about the exact location corresponding to the address. In a very similar way, addresses for Internet information packets have four fields that contain numbers and are separated by periods. These are called IP addresses. For example, the sequence of numbers

128.169.200.227

is an IP address. However, people generally can remember names better than numbers, so it is convenient to associate a name with such an IP address. In this case, the corresponding name is

csep10.phys.utk.edu.
The translation between the numbers used by the network, and the name more commonly used by people is done by a computer called a nameserver. The purpose of a nameserver is to look up addresses, so its function may be likened to directory assistance on the telephone system.
If I specify csep10.phys.utk.edu as an IP address to a network, the first thing that it does is call its "directory assistance" - that is, a nameserver - to get the number associated with that name (actually, most computers have a small list of address-name mappings stored locally that they first consult, and only go to an external nameserver if they don't find the address there). Thus, in most instances, we do not have to remember the numbers; we can just specify the corresponding name.


			Internet Addresses \| Numbers and Names
		Numbers and Names The address on a normal letter typically has several lines, each of which supplies different levels of information about the exact location corresponding to the address. In a very similar way, addresses for Internet information packets have four fields that contain numbers and are separated by periods. These are called IP addresses. For example, the sequence of numbers `128.169.200.227` is an IP address. However, people generally can remember names better than numbers, so it is convenient to associate a name with such an IP address. In this case, the corresponding name is `csep10.phys.utk.edu`. The translation between the numbers used by the network, and the name more commonly used by people is done by a computer called a nameserver. The purpose of a nameserver is to look up addresses, so its function may be likened to directory assistance on the telephone system. If I specify `csep10.phys.utk.edu` as an IP address to a network, the first thing that it does is call its "directory assistance" - that is, a nameserver - to get the number associated with that name (actually, most computers have a small list of address-name mappings stored locally that they first consult, and only go to an external nameserver if they don't find the address there). Thus, in most instances, we do not have to remember the numbers; we can just specify the corresponding name.