This document summarizes how to configure networking on CentOS including connecting to a network with NetworkManager, setting up local area networks, checking Ethernet connectivity, monitoring network traffic with Wireshark, setting up an Apache web server, monitoring server activities with Apache logs, installing and configuring a MySQL database server, and opening firewall ports for services. Key steps include installing NetworkManager, configuring TCP/IP, using ifconfig to check Ethernet status, starting httpd and MySQL servers, creating MySQL databases and tables, and granting user access to MySQL databases.

1. Centos Networking
By
Mohd yasin Abd Karim
yasin@yasin.my

2. Connecting to the Network with
NetworkManager
• The NetworkManager applet icon (upper left)
shows that NetworkManager is running.
• Check for NetworkManager
• $ rpm -qa NetworkManager*
• Install NetworkManager
• # yum install NetworkManager-gnome
NetworkManager-glib
• Start NetworkManager
• # service NetworkManager start
• # chkconfig NetworkManager on

3. Local Area Networks
• Planning, Getting, and Setting Up LAN hardware—
This entails choosing a network topology, purchasing the
equipment you need, and installing it (adding cards and
connecting wires or using wireless antennas).
• Configuring TCP/IP —To use most of the networking
applications and tools that come with Linux, you must
have TCP/IP configured. TCP/IP lets you communicate
not only with computers on your LAN, but also with any
computers that you can reach on your LAN, modem, or
other network connection (particularly via the Internet).

4. Is Your Ethernet Connection Up?
• Using the ifconfig command, you can determine
whether your Ethernet (and other network
interfaces) is up and running.
• # ifconfig
• # ifconfig eth0 up
• If your network interfaces are not running at all,
you can try to start them from the network
initialization script.
• # /etc/init.d/network restart

5. Watching LAN Traffic with
Wireshark
• Wireshark Network Analyzer.
• # wireshark &

6. Setting Web Server
• The Apache Web Server (httpd)
• Others web server
– Lighttpd
– Tclhttpd
– Thttpd
– XSP – can run ASP.NET
– Zope

7. Apache Server
• Make sure that Apache is installed
• $ rpm -qa | grep httpd
• A valid hostname is recommended if it is a
public Apache server.
• can edit the /etc/httpd/conf/httpd.conf file
and define the ServerName as your
computer’s IP address.

8. Apache Server
• To make the Web Server available to your
LAN, you can use your IP address instead
of www.example.com (e.g., ServerName
10.0.0.1). The :80 represents the port
number (which is the default)

9. Apache Server
• Start the httpd server. As root user, type the
following:
• # service httpd start
• To have httpd start every time you boot your
system, run the command as root user.
• # chkconfig httpd on
• To make sure that the Web Server is working,
open Firefox (or another Web browser),
• http://localhost/
• Check SELinux

10. Monitoring Server Activities
• adding the following lines to the /etc/httpd/conf/httpd.conf
file:
<Location /server-status>
SetHandler server-status
Order deny,allow
Deny from all
Allow from 127.0.0.1
</Location>
<Location /server-info>
SetHandler server-info
Order deny,allow
Deny from all
Allow from 127.0.0.1
</Location>

11. Analyzing Web-Server Traffic
• The webalizer package can take Apache
log files and produce usage reports for
your server.
• Those reports are created in HTML format
so you can display the information
graphically.
• # yum install webalizer
• # webalizer
• http://localhost/usage

12. MySQL
Database Server
• You need at least the mysql and mysql-server
packages installed
• mysql—This software package contains a lot of
MySQL client programs (in /usr/bin)
• mysql-server—This software package contains
the MySQL server daemon (mysqld) and the
mysqld startup script (/etc/init.d/mysqld)
• mysql-devel—This software package contains
libraries and header files required for developing
MySQL applications.

13. MySQL
• If MySQL isn’t installed yet, type the
following:
• # yum install mysql-server
• GUI software for connecting to a MySQL
server
• # yum install mysql-administrator
• To launch the MySQL Administrator
window, type mysql-administrator.

14. Starting the MySQL Server
• To start the MySQL server immediately,
• # service mysqld start
• To set the MySQL server to start each
time the computer reboots
• # chkconfig mysqld on

15. Checking That MySQL Server Is
Working
• # mysqladmin -u root -p version proc
• If the server were not running at the
moment
• # service mysqld restart

16. Working with MySQL Databases
• The mysql_install_db command starts you
off with two databases: mysql and test.
• Starting the mysql Command
• $ mysql -u root -p mysql

17. MySQL Command
• mysql> status
• To create a new database name, use the
CREATE DATABASE
• mysql> CREATE DATABASE allusers;
• mysql> SHOW DATABASES;
• mysql> USE allusers;

18. Create table
• mysql> CREATE TABLE name (
• -> firstname varchar(20) not null,
• -> lastname varchar(20) not null,
• -> streetaddr varchar(30) not null,
• -> city varchar(20) not null,
• -> state varchar(20) not null,
• -> zipcode varchar(10) not null
• -> );

19. Insert/View Data
• mysql> INSERT INTO name
• -> VALUES (’Jerry’,’Wingnut’,’167 E
Street’,
• -> ‘Roy’,’UT’,’84103’);
• mysql> SELECT * FROM name;

20. Displaying Selected Columns
• mysql> SELECT
firstname,lastname,zipcode FROM name;

21. Sorting Data
• mysql> SELECT * FROM name ORDER
BY lastname;

22. Updating and Deleting MySQL
Records
• mysql> UPDATE name SET
streetaddr="933 3rd Avenue" WHERE
firstname="Chris";
• mysql> DELETE FROM name WHERE
firstname="Chris";

23. Adding Users and Granting Access
• mysql> GRANT USAGE ON *.*
• -> TO yason@localhost IDENTIFIED BY
“yason123";
• #mysql -u yason –p
• have no privilege to work with any of the
databases
• mysql> GRANT
DELETE,INSERT,SELECT,UPDATE ON
allusers.*
• -> TO yason@localhost;

24. Opening Your Firewall
• Web Server—Port 80
• Mail Server—Port 25 (and possibly port 587)
• FTP Server—Ports 20 and 21
• DNS Server—Port 53 (if you’re supporting your
own DNS)
• SSH Server—Port 22 (allows secure login
service to administer the computer remotely or
remote users to add Web content or other server
content to the server)

25. Thank you
• http://www.yasin.my