How to Install and configure Centos6

[1] Here is the configuration Examples for CentOS6 that is compatible with Red Hat Enterprise Linux 6. 

Download ISO file ( CentOS-6.2-x86_64-bin-DVD1.iso ) for installation from the following site.  

http://ftp.riken.jp/Linux/centos/6.2/isos/x86_64/

 [2] Burn ISO file to DVD with an application on your computer and Make an Installation Disk. After finishing it, proceed to next step for installing CentOS6. 

I hope you guys will aware of Installing Centos6 so, I am moving to Initial Configs.

Initial Config 

[1] Create an admin user.  

[root@dlp ~]# useradd yuva

[root@dlp ~]# passwd yuva

Changing password for user yuva.

New UNIX password:                      # set password

Retype new UNIX password:         # Confirm

passwd: all authentication tokens updated successfully.

[root@dlp ~]# exit                        # logout

[2]Make a user (it's 'yuva' in this example) be only a user who can switch to root as an administration user. 

[root@dlp ~]# vi /etc/group        # line 11: add user name

 wheel:x:10:root,yuva 

[root@dlp ~]#vi /etc/pam.d/su 

#%PAM-1.0
auth            sufficient              pam_rootok.so

# Uncomment the following line to implicitly trust users in the "wheel" group.
#auth   sufficient       pam_wheel.so trust use_uid

# Uncomment the following line to require a user to be in the "wheel" group.
# uncomment the following line

auth           required             pam_wheel.so use_uid
auth           include              system-auth
account    sufficient           pam_succeed_if.so uid = 0 use_uid quiet
account      include           system-auth
password   include          system-auth
session      include           system-auth
session       optional         pam_xauth.so

Forwarding email for root to administration user 

[3] Configure that forwarding emails for root to administration user you set above.  

[root@dlp ~]#vi /etc/aliases        # Person who should get root's mail

# last line: uncomment and change to a user

root:yuva

[root@dlp ~]# newaliases  # Configuration change

Firewall

[1] If some firewalls are running in your LAN and iptables in the server is unnecessary, stop it.

[root@dlp ~]# /etc/rc.d/init.d/iptables stop

iptables: Flushing firewall rules:                   [ OK ]

iptables: Setting chains to policy ACCEPT: filter       [ OK ]

iptables: Unloading iptables modules:          [ OK ]

[root@dlp ~]# chkconfig iptables off

[root@dlp ~]# chkconfig ip6tables off