A DNS Overview
1 Introduction
That DNS DNS, pointing to web space is the domain IP, so that people can easily access to a service site through the domain name registration. IP address is a numerical address on the network identify the site, in order to facilitate memory, the use of the domain name instead of the IP address identifies the site address. DNS is the domain name to the IP address of the conversion process. Analytical work done by the DNS domain name server.
DNS also called domain names point to the server settings, and configure reverse IP domain name registration and so on. The point is to put it simply easy to remember domain names into IP, service is completed by the DNS server, the domain name is resolved to an IP address, and then a subdirectory binding domain on the IP address of the host.
The Internet address is the numeric IP address, DNS main role is to facilitate memory.
2 role
A DNS system is a network maintains an address database, which records the various correspondence between domain names and IP address of the host in order to provide a forward or reverse address lookup services to clients, namely the forward and reverse resolve resolution.
Forward Analysis: According to domain name check IP addresses that are specified domain name resolved to the corresponding IP address.
Reverse analysis: according to IP addresses with domain names, it will soon be resolved to the specified IP address corresponding to the domain name.
3 System Type
Caching name server: Also known as a cache server, access to domain name, IP address records by querying other domain name server, then the domain name query results to a local cache to improve the speed of repetitive queries.
Primary DNS Server: official server-specific DNS zone, unique. Mapping is responsible for maintaining a record of all domain names, IP addresses in the region.
From the Domain Name Server: also known as the secondary domain name server, which is maintained by domain name, IP address records from the primary domain name server.
4 BIND (the most widely used programs to provide domain name services DNS) configuration file
/etc/named.conf---------------------------- main configuration file
/etc/named.rfc1912.zones--------------- zone configuration file
/var/named/named.localhost------------ area data configuration file
Two forward resolution
1 networking, from yum repository to download and install BIND daemon
2 View ip address to enter the main configuration file to configure, save and exit configuration
3 enter regional profile configuration, configuration save and exit
4 enters the area configuration data files
Zone data file in / var / named directory, here not automatically generate new domain configuration file. We need to create a file name has been defined within the zone configuration file must be exactly the same. Creating ways to copy a template renamed, namely in the area defined data profile template configuration file name, named.localhost. Note that after the replication permission to be consistent, so use cp -p command.
5 /etc/resolv.conf original DNS server IP address to the IP address of
6 configuration is complete, turn off the firewall and enhanced security co-feature, start the service. Three domain names written parses the available host commands.
Three reverse lookup
Has been previously set to the master configuration file, simply set the area where the profile data and the profile region
A profile setting area
Set 2 data area profile, with the method of forward resolution profile data area
3 setup is complete, restart the service reverse analysis
Four master-slave synchronization
Master-slave synchronization from the zone data file server from the primary server to download from, save the file name can define their own, do not have to coincide with the main server, but it should be noted that, named by default with the service called " named "user identity to run, so be sure the user has write access to the named storage directory
1 as the main service from the server and configure the master configuration file
2 Configuration zone configuration file
3 main server configuration profile region
4 Turn off the firewall from the server, enhanced functionality, restart the service, if there are regional data configuration file to view the slavers directory
5 Change the DNS server address, analytical testing
