Introduction to Networking for NonStop NS-Series Servers (H06.03+, J06.03+)

Networking Concepts

Introduction to Networking for HP Integrity NonStop NS-Series Servers—529874-003

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Name Resolution

For convenience, hosts are often referred to by name; in addition, for the world wide

web, universal resource locators (URLs) locate a website location. The process of

finding the IP address associated with either a host or a URL is a process of name-to-

address mapping, is also called name resolution. There are two methods of resolving

names, by:

•

HOSTS File

•

Domain Name System (DNS)

HOSTS File

A HOSTS file is an ASCII file on your system, by default in ZTCPIP (Guardian) or /etc

(OSS) that lists the various host names associated with the IP addresses on the

system. To use a HOSTS file for address resolution, you must configure the TCP/IP

subsystem to use that HOSTS file; the default is for the TCP/IP subsystems is to use

the Domain Name System (DNS).

See the TCP/IPv6 Configuration and Management Manual for procedures about

configuring the NonStop TCP/IPv6 subsystem to use the HOSTS file. See the TCP/IP

Configuration and Management Manual for procedures about configuring the NonStop

TCP/IP subsystem to use the HOSTS file.

Domain Name System (DNS)

The Internet has created an ever-increasing demand for IP addresses, and IP address

management has presented a challenging task for administrators. In the past,

administrators could manage the IP addresses in a single file containing all the host

information (HOSTS File) with name-to-address mappings for every host connected to

the network. Now assigning and maintaining new IP addresses and resolving domain

names to IP addresses have become difficult and cumbersome tasks.

An effective solution to this problem is the Domain Name System (DNS), a distributed

database that implements a name hierarchy for TCP/IP-based networks. DNS defines

the rules for name syntax in a hierarchical name space and for delegation of authority

over names. A name server is a server program that maps domain names to IP

addresses. A set of DNS name servers operating at multiple sites co-operatively solve

the domain name to IP address mapping problem.

Every time you use a domain name, a DNS service translates the name into the

corresponding IP address. For example, the domain name www.sample.com translates

to 188.135.212.3.

To use the domain name system, you must assign a name, in ARPANET standard

format, to each system on the network or internetwork. You configure this name in your

network configuration scripts. (See the TCP/IPv6 Configuration and Management

Manual and the TCP/IP Configuration and Management Manual for details.)