A brief account of the application of DNS service in Network

Part I: Installation and simple use of DNS

Introduction to DNS

DNS is the abbreviation of domain Name System, is a core service of the Internet, it is a distributed database that can map domain name and IP address to each other, it can make people access the Internet more conveniently, without remembering the IP string that can be read directly by machine.

DNS uses TCP and UDP port number is 53, mainly using UDP, backup between servers using TCP

Position

The DNS service is provided by a computer that has the DNS server-side software installed. Server-side software can be either a class-based Linux operating system or a windows-based operating system. After you install the DNS service software, you can create a zone file in the location you specify, which is a file that contains the name to the IP address resolution record in this domain, as the contents of the file may be:

Primary name server = DNS2 (host name of the primary server is)

Serial = 2913 (the current serial number is 2913.) The role of this serial number is when the auxiliary domain name server to copy this file, if the number added to copy)

Refresh = 10800 (3 hours) (secondary domain server queries a primary server every 3 hours)

Retry = 3600 (1 hour) (when the secondary domain name server tries to query for updates on the primary server and the connection fails, the secondary domain name server accesses the primary domain name server every 1 hours)

expire = 604800 (7 days) (secondary domain name server deletes the record in the 7 day after the failed update to the main service.) ）

Default TTL = 3600 (1 hour) (the cache server holds records for 1 hours.) That is to tell the cache server to save the domain resolution record is 1 hours)

DNS Installation

Experimental environment:

Red Hat Enterprise Linux 5.4 32-bit

Three files are used for DNS installation

Bind-9.3.6-4.p1.el5

bind-chroot-9.3.6-4.p1.el5.i386.rpm

caching-nameserver-9.3.6-4.p1.el5.i386.rpm

[Root@localhost ~]# Mkdir/mnt/cdrom//Set up disc mount point

[Root@localhost ~]# mount/dev/cdrom/mnt/cdrom///Mount CD

[Root@localhost ~]# cd/mnt/cdrom/server/

[Root@localhost server]# RPM-IVH bind-9.3.6-4.p1.el5.i386.rpm

[Root@localhost server]# RPM-IVH bind-chroot-9.3.6-4.p1.el5.i386.rpm

[Root@localhost server]# RPM-IVH caching-nameserver-9.3.6-4.p1.el5.i386.rpm

[Root@localhost server]# Cd/var/named/chroot/etc

[Root@localhost etc]# rpm-ql Bind

/etc/named.conf/* But there is no such profile and we need to copy it ourselves.

[Root@localhost etc]# cp-p named.caching-nameserver.conf named.conf

/* In the copy we need to use the-p parameter, is named.conf inherited the source file properties, otherwise the service is not available.

Edit configuration file vim/var/named/charoot/etc/named.conf