How to change mail server IP temporarily

go to whm >> exim configuration editor

then check the option

"Send outgoing mail from the ip that ..."

then go /etc/mailips and add the IP

==========

`There are two options to switch the mail server IP in Cpanel.

Option #1

Login to WHM

Click Exim Configuration Editor

Check the box next to:
"Send outgoing mail from the ip that matches the domain name in /etc/mailips (*: IP can be added to the file to change the main outgoing interface)"

Save Changes

Then edit the file /etc/mailips
nano /etc/mailips
from shell and add:

*: ReplacewithnewIP

Restart exim

service exim restartOption #2

Login to Shell

Access the Exim configuration file:
nano /etc/exim.confLocate remote_smtp

The default setup will look like:

remote_smtp:
driver = smtp
interface = ${if exists {/etc/mailips}{${lookup{$sender_address_domain}lsearch{/etc/mailips}{$value}{}}}{}}
helo_data = ${if exists {/etc/mailhelo}{${lookup{$sender_address_domain}lsearch{/etc/mailhelo}{$value}{$primary_hostname}}}{$primary_ho stname}}Change to:

remote_smtp:
driver = smtp
#interface = ${if exists {/etc/mailips}{${lookup{$sender_address_domain}lsearch{/etc/mailips}{$value}{}}}{}}
#helo_data = ${if exists {/etc/mailhelo}{${lookup{$sender_address_domain}lsearch{/etc/mailhelo}{$value}{$primary_hostname}}}{$primary_ho stname}}
interface = 11.1.1.1.1 # Change to your server IP address.
Save changes and exit.

Restart Exim

=================

Named Error

root@smx3.hostdime.com.mx(~)$ /etc/init.d/named restart
Stopping named: [ OK ]
Starting named:
Error in named configuration:
zone clone2.dizinc.com.zz/IN: loaded serial 2009021100
zone phpinfotest.com/IN: loaded serial 2009021100
zone transportesmiguel.com/IN: loaded serial 2009021100
zone grupoferrer.com/IN: loaded serial 2009021100
zone jyaa.com.mx/IN: loaded serial 2009021100
zone avpca.org/IN: loaded serial 2009021100
zone hawkanime.net/IN: loaded serial 2009021100
zone nortechengineering.com.mx/IN: loaded serial 2009021100
.
.
.
zone heraldodelbajio.com/IN: loading master file /var/named/heraldodelbajio.com.db: file not found
.
.
.

===========

actually the error is due to some incorrect entries in the /etc/named.conf
1.first check is there any entry for heraldodelbajio.com.db i.e in the error log
2.add it to /etc/named.conf
3.remove or comment following entries

# key "rndckey" {
# algorithm hmac-md5;
# secret "53Ard+LKadYqYxNPTZoMpQ==";
# };
#
# controls {
# inet 127.0.0.1 port 953
# allow { 127.0.0.1; } keys { "rndckey"; };
# };

rndc reload
/scripts/fixrndc
then restart named
this will fix the issue

Check a web page exists

Here is a short method to check if a web page exists from a perl script,
this script will test the existense of a page and do something as a result:

==========

#!/usr/bin/perl
use LWP::Simple;
print “Content-Type: text/htmlnn”;

$url = “ http://site.com/“;

if (head($url)) {
# ok document exists
print “OK: found $url”;
} else {
# something is not well
print “PROBLEM: $url is missing”;
}

=============

How to reset mysql root password ?

1. Stop/ kill the mysqld
# service mysql stop
#pkill -9 mysqld

2) Start the mysql insafe mode as follows

# /usr/sbin/mysqld --skip-grant-tables --user=root &

3) Now update the mysql user tables and root password as follows

#mysql
mysql>use mysql;
mysql>UPDATE user SET Password=PASSWORD('YOUR_PASSWORD') WHERE Host='localhost' AND User='root';
mysql>flush privileges;

Now add the new password “YOUR_PASSWORD” in /root/.my.cnf and start mysql

# service mysql start


// To grant privilege on mysql table

grant EXECUTE on procedure lenbelle_mydbr.sp_MyDBR_UserPassword to 'lenbelle_mydbru'@'localhost';

where lenbelle_mydbr.sp_MyDBR_UserPassword = procedure that having problem
lenbelle_mydbru = dbuser

Mysql optimization

MySQL Optimization

Login to your server as root and do a backup of my.cnf mySQL configuration file:
# cp /etc/my.cnf /etc/my.cnf.backup

Edit my.cnf file using nano or other text editor:
# nano /etc/my.cnf

You can use that configuration to optimize default configuration:

[mysqld]
port = 3306
socket = /var/lib/mysql/mysql.sock
skip-locking
skip-innodb
query_cache_limit=8M
query_cache_size=256M
query_cache_type=1
max_connections=500
max_user_connections=100
interactive_timeout=60
wait_timeout=60
connect_timeout=30
thread_cache_size=128
key_buffer=16M
join_buffer=1M
max_allowed_packet=16M
table_cache=1024
record_buffer=1M
sort_buffer_size=2M
read_buffer_size=2M
max_connect_errors=100
# Try number of CPU's*2 for thread_concurrency
thread_concurrency=2
myisam_sort_buffer_size=64M
#log-bin
server-id=1

[mysqldump]
quick
max_allowed_packet = 16M

[mysql]
no-auto-rehash

[isamchk]
key_buffer = 256M
sort_buffer_size = 256M
read_buffer = 2M
write_buffer = 2M

[myisamchk]
key_buffer = 256M
sort_buffer_size = 256M
read_buffer = 2M
write_buffer = 2M

[mysqlhotcopy]
interactive-timeout

Save and exit

How to disable telnet

Login as root to your server, now:

Edit /etc/xinetd.d/telnet
# nano /etc/xinetd.d/telnet

Search for: "disable = no" (you can use Ctrl+W) ,
Change it to: disable = yes

Save and Exit

Restart xinted
# /etc/rc.d/init.d/xinetd restart

How To Install Rkhunter

If you are running a Web Server, Mail Server, Hosting Server or VPS Server and you need to provide security against rootkits, so we recommend you to install Rkhunter.

RKhunter is compatible with the most popular Hosting Control Panels like cPanel, Plesk, Ensim etc.

"Rootkit scanner is scanning tool to ensure you for about 99.9%* you're clean of nasty tools.
This tool scans for rootkits, backdoors and local exploits by running tests like:
- MD5 hash compare
- Look for default files used by rootkits
- Wrong file permissions for binaries
- Look for suspected strings in LKM and KLD modules
- Look for hidden files
- Optional scan within plaintext and binary files
Rootkit Hunter is released as GPL licensed project and free for everyone to use.
* No, not really 99.9%.. It's just another security layer"
( http://www.rootkit.nl/ )


Install Rkhunter:
# wget http://downloads.rootkit.nl/rkhunter-1.2.7.tar.gz
# tar -zxvf rkhunter-1.2.7.tar.gz
# cd rkhunter-1.2.7
# ./installer.sh

Update Rkhunter:
# rkhunter --update

Run a Test Scan (help to prevent false positives):
# /usr/local/bin/rkhunter -c

Setup a daily scan report:
# nano /etc/cron.daily/rkhunter.sh

and add it:
#!/bin/bash
(/usr/local/bin/rkhunter -c --cronjob 2>&1 mail -s "Daily Rkhunter Scan Report" email@domain.com)

Change premissions:
# chmod +x /etc/cron.daily/rkhunter.sh

rkhunter version:

rkhunter --version