DNS is nothing but the numerical form of IP address which can be easily remembered and used. It can resolve full domain name from the IP address and vice-versa. There is master name server and slave name server.
Configuration of DNS server
To install DNS server we need to install bind package from terminal using following command:
# yum search bind
It will list all available bind packages. From all packages we have installed bind.i686 : The Berkeley Internet Name Domain (BIND) DNS (Domain Name System) server. Command is as follows.
# yum install bind.i686
After the installation we need to configure named.conf file which is lying in /var/named/chroot/etc/named.conf
- Here we will create two zones in named.conf one will be forward zone and another will be reverse zone.
- After that we need to create both zones’ file separately.
Here is the named.conf file configuration.
In the beginning of the configuration file all file options are provided and it provides all those files stored on the system. We have disabled IPv6 support. Here logging section provides all log messages so that it can be helpful for configuration as well as troubleshooting.
Now we have added two zones in named.conf now it is time to create both zones’ individual file. It has to be created in /var/named/chroot/var/named folder.
I have created two zone files as follow in above mentioned directory.
It is compulsory to create both these files before starting the named service. So create these two files in that particular folder as mentioned above. And the configure it as mentioned in below fig.
You can create those files using nano command which is in-build an editor.
Below figures describes the configuration of forward zone and reverse zone.
Here as we can see NS represents the name server chintangurjar.com in which we have integrated NS1, WWW, MAIL and SMTP for chintangurjar.com
These records show the address of the server chintangurjar.com. Here PTR is the pointer to chintangurjar.com and this is reverse zone configuration file.
- Forward zone just keeps all the information about zone and their standard records.
- Reverse zone is specially created to perform reverse look up. Records of these zones are derived from address.
Once these zone files created we need to start DNS service by restarting or starting named service. Command is showing below.
#service named restart
Now we will be checking from client side that, if it is working from client side or not. For that XP machine will be used and command to check DNS is NSLOOKUP
Clearly, NSLOOKUP command shows the whole zone information in client machine Windows XP.
Self Critical Evaluation
- After editing named file when I tried to restart the named service it was giving me permission error such as “could not configure root hints from 'named.ca' permission denied”.
- I resolved that error by typing following command.
# chown named: named /var/named/chroot/var/named/named.ca
Thus, Whole DNS task can be accomplished. Now we will move towards postfix.