How to check if ports have got open after IPTables rules

Verify that port is open

Run following command:
netstat -tulpn | less
Make sure iptables is allowing port 80 / 110 / 143 connections:
iptables -L -n

Refer to iptables man page for more information about iptables usage and syntax:
man iptables

IPTables CentOS5.6 - port 80, 143, 443 allowed or open

I had my webserver setup perfectly and it was working fine but it was not accessible from outside. It was IPtables blocking the same. I read on internet about the rules for IpTables to allow access to port 80,443,143. below mentioned are the rules.

-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 80 -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 443 -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 143 -j ACCEPT

But even after applying these rules things were not working because I was appending these rules after the rule

-A RH-Firewall-1-INPUT -j REJECT --reject-with icmp-host-prohibited


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I think (I don't know for sure) the rule for icmp shall always be at the last. Any rule after that to allow access to network resources will not get effective.

If I am wrong please correct.

You can refer to http://www.cyberciti.biz/faq/howto-rhel-linux-open-port-using-iptables/ for more information on IPTables.

Create WebServer CentOS5.x - PHP, MySQL, Apache2 installation

Now we install Apache with PHP (this is PHP):

yum install php php-devel php-gd php-imap php-ldap php-mysql php-odbc php-pear php-xml php-xmlrpc curl curl-devel perl-libwww-perl ImageMagick libxml2 libxml2-devel

Then edit /etc/httpd/conf/httpd.conf:

vi /etc/httpd/conf/httpd.conf

and change DirectoryIndex to

[...]
DirectoryIndex index.html index.htm index.shtml index.cgi index.php index.php3 index.pl
[...]

Now configure your system to start Apache at boot time:
chkconfig --levels 235 httpd on
Start Apache:
/etc/init.d/httpd start

INSTALL MYSQL:

yum1 install mysql mysql-devel mysql-server

MySQL Change root Password

mysqladmin command to change root password

If you have never set a root password for MySQL server, the server does not require a password at all for connecting as root. To setup root password for first time, use mysqladmin command at shell prompt as follows:
$ mysqladmin -u root password NEWPASSWORD

However, if you want to change (or update) a root password, then you need to use the following command:
$ mysqladmin -u root -p'oldpassword' password newpass
For example, If the old password is abc, you can set the new password to 123456, enter:

$ mysqladmin -u root -p'abc' password '123456'

Change MySQL password for other users
To change a normal user password you need to type (let us assume you would like to change password for user vivek) the following command:
$ mysqladmin -u vivek -p oldpassword password newpass


Changing MySQL root user password using MySQL sql command
This is another method. MySQL stores username and passwords in user table inside MySQL database. You can directly update password using the following method to update or change password for user vivek:
1) Login to mysql server, type the following command at shell prompt:
$ mysql -u root -p
2) Use mysql database (type command at mysql> prompt):
mysql> use mysql;
3) Change password for user vivek, enter:
mysql> update user set password=PASSWORD("NEWPASSWORD") where User='vivek';
4) Finally, reload the privileges:
mysql> flush privileges;
mysql> quit
Copied from: http://www.cyberciti.biz/faq/mysql-change-root-password/

How to Enable .htaccess in Apache2

http://ubuntuforums.org/showthread.php?t=47669

Re: Enable .htaccess in Apache2

---

Found the solution!! Apache2 in general, or it might be specifically to Ubuntu, is configured slightly differently than Apache1.x.. at least from what I've seen in the default installs in RH, FC, Mandrake, etc (I'm not Linux or Apache expert).

I went to /etc/apache2/sites-available and edited the file default
There you'll find:

Code:

NameVirtualHost *
<VirtualHost *>
        ServerAdmin admin@site.com

        DocumentRoot /var/www/
        <Directory />
                Options FollowSymLinks
                AllowOverride None
        </Directory>
        <Directory /var/www/>
                Options Indexes FollowSymLinks MultiViews
                AllowOverride All
                Order allow,deny
                allow from all
                # This directive allows us to have apache2's default start page
                # in /apache2-default/, but still have / go to the right place
                # Commented out for Ubuntu
                #RedirectMatch ^/$ /apache2-default/
        </Directory>

Default for AllowOverride is none, should be all

How to find the Linux Distro Name and version

Some distros put a '*-release' or '*-version' file 
in /etc. Here are some examples: 

/etc/redhat-release 
/etc/debian_version 
/etc/SuSE-release 
/etc/slackware-version 
/etc/gentoo-release 

You could do 'cat /etc/*-release' or 'cat /etc/*-version'. 

IPtables the play is dangerous and frustrating...yet find the way how to enable outbound traffic for port 3306 mysql

1. vi /etc/sysconfig/iptables 
To allow inbound traffic add this rule:  -A INPUT -p tcp -m tcp --dport 3306 -j ACCEPT
To allow outbound traffic add this rule:  -A OUTPUT -p tcp -m tcp --dport 3306 -j ACCEPT 

Now restart IPtables:  /etc/init.d/iptables restart