Addition/Setup.Bind.As.Cache.DNS.Server

From iRedMail

Mission

To configure a caching nameserver on a iRedMail server itself.

Advantage

Reduces the delay in domain name resolution drastically as the requests for frequently accessed domain are served from cache.

Working

"named" gets a request for domain resolution.

It checks whether the request can be satisfied from cache. If the answer is in cache and not stale, the request is satisfied from cache itself saving a lot of time

If request can't be satisfied from cache, named queries the first parent. If it replies with the answer, then named will cache the response and subsequent requests for the same domain name will be satisfied from the cache.

In case first parent fails to reply, named will query the second parent and so on.

How to install

We choose BIND which is the most common package on DNS server.

To check the package present or not on the system, just using

rpm -qa |grep bind

rpm -qa |grep caching-nameserver

by default on iRedMail server, the result is:

[root@mail ~]# rpm -qa |grep bind

ypbind-1.19-12.el5

bind-libs-9.3.6-4.P1.el5_4.2

bind-utils-9.3.6-4.P1.el5_4.2

the package we need on cache named server is

bind

bind-chroot

bind-util

caching-nameserver

If they are not present on your system, install using

yum install caching-nameserver bind-chroot

all the components we need will be installed