Linux System Services 2 DNS infrastructure and domain Name System architecture

1 Domain Name

1 For example, www.LinuxCast.net, actually domain name is only a part of the back, but we are generally called the entire domain name

2 for the domain name, we generally use. To split, the strict domain name the last one still has one. But we all simply omit

3 domain name is divided into three parts

Host name one of the hosts in this domain is WWW for Web servers, but there are ftp,mail and so on.

Domain Name

Type identifies the type of this domain name, and is more common with COM, net, org, edu, gov

2 DNS

1 each domain name actually represents an IP address, such as Www.LinuxCast.net IP as 1.1.1.1 (assuming)

2 DNS (Domain Name System), which has DNS to provide

3 For example I want to visit www.LinuxCast.net

The first step is to request a DNS server

Second step DNS returns the IP address of the current domain name

Third step the host to access the current Web site via IP address

3 DNS Clients

1 Our daily use of support network computers are generally used as a DNS client, applications, services, processes, and so on through the function of the underlying functions of the DNS server to initiate queries to the specified domain name for resolution

2 Linux generally use the gethostbyname () provided by the bottom of the system for domain resolution

3 parsing is based on the following several ways

File (/etc/hosts. /etc/networks)

Dns

Nis

4 We can use the configuration file/etc/nsswhich,conf to control the order of the query, the default is the first file hosts, the second is the DNS