DNS configuration on CentOS /RedHat 6.2

Step 1
#ifconfig

 Step 2
# vi /etc/hosts

Step3
# vi /etc/sysconfig/network

Step 4
#vi /etc/resolv.conf

Step 5
#service network restart

Step 6
#yum install bind* -y

Step 7
#vi /etc/named.conf

 Step 8
#vi /etc/named.rfc1912

Step 9
#cd /var/named/
#ls
#cp named.localhost forward.zone
#cp named.loopback reverse.zone

Step 10
# vi forward.zone 

Step 11
#vi reverse.zone

Step 12
# dig dns.mydns-setup.com

Server’s Serial Number from command line – RedHat/CentOS

To get service/serial number from command in linux run command below. The first result is the service tag which usually in alphanumeric.


[server@dev-test ~] # dmidecode | egrep -i “serial|product”
output example:
Product Name: PowerEdge R710
Serial Number: 378CDE1
……..
Product Name: 0DCR13
Serial Number: ..ABC980CDE4545XYZ.
Serial Number: AB66X66
Serial Number: Not Specified
Serial Number: Not Specified
Port Type: Serial Port 11204A Compatible
……

Postfix Mail Server on RedHat 6 /CentOS 6

In this setup:
IP address of server = 161.101.234.62
Hostname = mail
Domain Name = yeswedeal.com
Full Computer name (FQDN) = mail.yeswedeal.com

Note: Make sure DNS Server is properly configured.

Install Required package:
yum install postfix dovecot squirrelmail http  -y

# vim  /etc/postfix/main.cf
inet_interface   =   all
# inet_interface   =  localhost
mydestination =  $myhostname,  localhost.$mydomain, localhost,  $mydomain
home_mailbox =  Maildir/


vim  /etc/dovecot.conf
protocols  =  imap  imaps  pop3  pop3s
mail_location  = maildir:~/Maildir
pop3_uidl_format  =  %09Xu%09Xv
imap_client_workarounds = outlook-idle  delay-newmail  netscape-eoh
pop3_client_workarounds = outlook-no-nuls    oe-ns-eoh

vim  /etc/squirrelmail/config.php
$domain                       = ‘yeswedeal.com’;
$imapServerAddress    = ‘161.101.234.62’;
$smtpServerAddress    = ‘161.101.234.62’;
$default_folder_prefix   = ‘Maildir/’;

service  postfix  restart
service   dovecot   restart
service httpd  restart

Linux Easy Admin Utilities For RHEL, FEDORA, CENTOS, OPENSUSE, UBUNTU, DEBIAN, SLACKWARE

The IT Infrastructure Analyst, IT Ops Engg., Systems Admin, IT Support Engg., IT Helpdesk Engg. Companies changes and Job titles change but the responsibilities over lap and mix. My quest to make work fun, simple, joy and easy has lead to write, collect, source and use various scripts and tools that will help in a very easy and fun filled work flow with computers and IT systems.

This project is to write and collect tools and utilities that make System Administration easy and simple. If a hard working Admin cannot have a beautiful wallpaper on his screen then the Admin can at least have one complete set utility tools that make the brow sweat free and achieve deadlines.

The current list of tools:

Password Generator<br> Network & Firewall Auditor<br> Disk Auditor<br> FS Auditor<br> General System Auditor

Download at:

http://code.google.com/p/linux-easy-admin-utilities/
http://sourceforge.net/projects/lnxesyadmutil/

 # wget http://linux-easy-admin-utilities.googlecode.com/files/linux-easy-admin-util-v0.2.tar.gz
# tar -zxvf linux-easy-admin-util-v0.2.tar.gz
# cp easy-admin/* /usr/local/bin/
# adtdepchk

genadtchk - General Audit Checker: This script generates a simple information information about your system. Basic system, Memory, Disk, File System, Network data is audited.
dksadtchk - Disk Audit Checker: This script generates a complete and compressive information about your systems disk and storage. Total disks at boot time, contained partitions, partitions used, removable disks, capacity and free capacity etc.
fsadtchk - File System Audit Checker: This script generates a complete and compressive information about the systems FS usage and current mounted, total available, type, size, free, and space occupying number one folder or file from the FS.
netadtchk - Network Audit Checker: This script  generates a complete and compressive information about the network interfaces - hardware, virtual, local and other , firewall and its status, outgoing firewall status, current process that are having listening processes, port - ip - process - executable table, IPV4/6 feature, forwarding, masquerading for the system.