Monitoring network connections with iptstate

On Fedora 13
#yum -y install iptstate
#iptstate

How to check kernel version ?

[root@localhost ~]# uname -r
2.6.33.6-147.2.4.fc13.i686.PAE

Fedora Documentation

http://docs.fedoraproject.org/en-US/index.html

Monitoring active network connections with tcptrack

#yum -y install tcptrack

How to use?
tcptrack -i "interface name"

#tcptrack -i eth0

How to check message error about IRQ show in terminal ?

The system (CentOS 5.5) show message error "localhost kernel: Disabling IRQ #209"
Use the typed command (as root) 'lspci -v'





[root@localhost ~]# lspci -v
00:00.0 RAM memory: nVidia Corporation MCP61 Memory Controller (rev a1)
Subsystem: ASRock Incorporation 939NF6G-VSTA Board
Flags: bus master, 66MHz, fast devsel, latency 0
Capabilities: [44] HyperTransport: Slave or Primary Interface
Capabilities: [dc] HyperTransport: MSI Mapping

00:01.0 ISA bridge: nVidia Corporation MCP61 LPC Bridge (rev a2)
Subsystem: ASRock Incorporation 939NF6G-VSTA Board
Flags: bus master, 66MHz, fast devsel, latency 0

00:01.1 SMBus: nVidia Corporation MCP61 SMBus (rev a2)
Subsystem: ASRock Incorporation 939NF6G-VSTA Board
Flags: 66MHz, fast devsel, IRQ 11
I/O ports at dc00 [size=64]
I/O ports at 5000 [size=64]
I/O ports at 6000 [size=64]
Capabilities: [44] Power Management version 2

00:01.2 RAM memory: nVidia Corporation MCP61 Memory Controller (rev a2)
Subsystem: ASRock Incorporation 939NF6G-VSTA Board
Flags: 66MHz, fast devsel

00:02.0 USB Controller: nVidia Corporation MCP61 USB Controller (rev a2) (prog-if 10 [OHCI])
Subsystem: ASRock Incorporation 939NF6G-VSTA Board
Flags: bus master, 66MHz, fast devsel, latency 0, IRQ 217
Memory at dfeff000 (32-bit, non-prefetchable) [size=4K]
Capabilities: [44] Power Management version 2

00:02.1 USB Controller: nVidia Corporation MCP61 USB Controller (rev a2) (prog-if 20 [EHCI])
Subsystem: ASRock Incorporation 939NF6G-VSTA Board
Flags: bus master, 66MHz, fast devsel, latency 0, IRQ 209
Memory at dfefec00 (32-bit, non-prefetchable) [size=256]
Capabilities: [44] Debug port
Capabilities: [80] Power Management version 2

00:04.0 PCI bridge: nVidia Corporation MCP61 PCI bridge (rev a1) (prog-if 01 [Subtractive decode])
Flags: bus master, 66MHz, fast devsel, latency 0
Bus: primary=00, secondary=01, subordinate=01, sec-latency=32
I/O behind bridge: 0000e000-0000efff
Memory behind bridge: dff00000-dfffffff
Prefetchable memory behind bridge: 80000000-800fffff
Capabilities: [b8] #0d [0000]
Capabilities: [8c] HyperTransport: MSI Mapping

How to check directory, file size in linux

Picture 1 check partition sizes : df -h

Picture 2 check directory size : du -s -h /var/log/squid/

Picture 3 check every directory and file sizes under a dir : du -s -h /var/log/squid/*

Picture 4 check individual size size : du -s -h /var/log/squid/access.log

View and Check Who Currently Login on SHH

check SSH connection using port number:
#lsof -i :22
or
check SSH connection using name:
#lsof -i :ssh

Credit by labtestproject.com

Set MySQL Passwords And Configure phpMyAdmin

[root@server1 tmp]# mysql_secure_installation

NOTE: RUNNING ALL PARTS OF THIS SCRIPT IS RECOMMENDED FOR ALL MySQL
SERVERS IN PRODUCTION USE! PLEASE READ EACH STEP CAREFULLY!


In order to log into MySQL to secure it, we'll need the current
password for the root user. If you've just installed MySQL, and
you haven't set the root password yet, the password will be blank,
so you should just press enter here.

Enter current password for root (enter for none):
OK, successfully used password, moving on...

Setting the root password ensures that nobody can log into the MySQL
root user without the proper authorisation.

Set root password? [Y/n] <-- ENTER
New password: <-- yourrootsqlpassword
Re-enter new password: <-- yourrootsqlpassword
Password updated successfully!
Reloading privilege tables..
... Success!


By default, a MySQL installation has an anonymous user, allowing anyone
to log into MySQL without having to have a user account created for
them. This is intended only for testing, and to make the installation
go a bit smoother. You should remove them before moving into a
production environment.

Remove anonymous users? [Y/n] <-- ENTER
... Success!

Normally, root should only be allowed to connect from 'localhost'. This
ensures that someone cannot guess at the root password from the network.

Disallow root login remotely? [Y/n] <-- ENTER
... Success!

By default, MySQL comes with a database named 'test' that anyone can
access. This is also intended only for testing, and should be removed
before moving into a production environment.

Remove test database and access to it? [Y/n] <-- ENTER
- Dropping test database...
... Success!
- Removing privileges on test database...
... Success!

Reloading the privilege tables will ensure that all changes made so far
will take effect immediately.

Reload privilege tables now? [Y/n] <-- ENTER
... Success!

Cleaning up...



All done! If you've completed all of the above steps, your MySQL
installation should now be secure.

Thanks for using MySQL!


[root@server1 tmp]#
[root@server1 tmp]#vi /etc/httpd/conf.d/phpmyadmin.conf
#
# Web application to manage MySQL
#

#
# Order Deny,Allow
# Deny from all
# Allow from 127.0.0.1
#

Alias /phpmyadmin /usr/share/phpmyadmin
Alias /phpMyAdmin /usr/share/phpmyadmin
Alias /mysqladmin /usr/share/phpmyadmin


[root@server1 tmp]#vi /usr/share/phpmyadmin/config.inc.php
[...]
/* Authentication type */
$cfg['Servers'][$i]['auth_type'] = 'http';
[...]


credit by howtoforge.com

Install Apache, MySQL, phpMyAdmin on CentOS 5.5

#rpm --import http://dag.wieers.com/rpm/packages/RPM-GPG-KEY.dag.txt
#cd /tmp
#wget http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.1-1.el5.rf.i386.rpm
#rpm -ivh rpmforge-release-0.5.1-1.el5.rf.i386.rpm
#yum install ntp httpd mysql-server php php-mysql php-mbstring php-mcrypt phpmyadmin

credit by howtoforge.com

vi / vim show line number command

:set number
or
:set nu