CS & IT Solutions

How to Install and Configure Vsftpd Ftp Server on RHEL 6/ CentOS 6.2/ Ubuntu 11.10/ Fedora /Debian. VSftpd (Very Secure FTP Daemon) is an FTP server for Linux distributions. Vsftpd is the default FTP server is the Fedora, RHEL, CentOS, Ubuntu, NimbleX Linux distributions. It is not just secure as the name suggests but also delivers excellent performance by consuming less memory.

In this tutorial, i will show how to install and configure Vsftpd service by adding ftp users and locking the directory to individual users on Red Hat Enterprise Linux 6 (RHEL 6), Ubuntu, CentOS and Fedora.
Default ftp port : 21
Default configuration file : /etc/vsftpd.conf

Basic Vsftpd commands on RHEL/CentOS/Fedora

1. Install the Vsftpd service.

[root@rhel6 ~]# yum install vsftpd

2. Start Vsftpd Service :

[root@rhel6 ~]# service vsftpd start Read the rest of this entry »

If you are hosting several web sites, for security reason, you may want the webmasters to access their own files only. One of the good way is to give them FTP access by setup of VSFTPD virtual users and directories. This article describes how you can do that easily.
(See also: Setup of VSFTPD virtual users – another approach)

1. Installation of VSFTPD

For Red Hat, CentOS and Fedora, you may install VSFTPD by the command

# yum install vsftpd

For Debian and Ubuntu,

# apt-get install vsftpd

2. Virtual users and authentication

We are going to use pam_userdb to authenticate the virtual users. This needs a username / password file in `db’ format – a common database format. We need `db_load’ program. For CentOS, Fedora, you may install the package `db4-utils’:

# yum install db4-utils

For Ubuntu,

# apt-get install db4.2-util

To create a `db’ format file, first create a plain text file `virtual-users.txt’ with the usernames and passwords on alternating lines:

mary
123456
jack
654321

Then execute the following command to create the actual database:

# db_load -T -t hash -f virtual-users.txt /etc/vsftpd/virtual-users.db

Now, create a PAM file /etc/pam.d/vsftpd-virtual which uses your database:

auth required pam_userdb.so db=/etc/vsftpd/virtual-users
account required pam_userdb.so db=/etc/vsftpd/virtual-users Read the rest of this entry »

Squid is a proxy server and web cache daemon. It has a wide variety of uses: caching web, filtering traffic, caching DNS and other computer network lookups for a group of people sharing network resources.

Squid is primarily designed to run on Unix-like systems but it also runs on Windows-based systems. In this tutorial I’ll show you how to install and configure squid proxy server to run under Linux and FreeBSD.

A proxy server software is based on the TCP/IP protocol. It monitors a special port such as 3128 or 8080. A computer who runs a proxy server software is called a proxy server. If other computer want to connect to Internet through the proxy server, it should know the proxy server’s IP address and proxy port.

1. Squid Installation

Squid source code is available from squid-cache.org.Installation instructions are available in the ReadMe file in the source tar file. There is also binary packages for CentOS, Fedora, Red Hat Enterprise Linux, Ubuntu, Debian, FreeBSD and NetBSD.

To install Squid under CentOS/Fedora/RHEL, enter:

yum install squid

To install Squid under Debian/Ubuntu, enter: Read the rest of this entry »

Manage Time in Ubuntu Through Command Line

What if you would like to manage your computer’s time in Ubuntu? It’s easy if you are in a graphical desktop environment. But what if you are on the command line? For example, in Ubuntu Server? Well, it is easy as well. A very helpful, everything-in-one-place resource is Ubuntu Time.

View Time

To view the current date and time, the following command will be enough

date

Set Time

To change time means to set a new time. To set time in Ubuntu (or any Linux), just run the following command

sudo date newdatetimestring

where newdatetimestring has to follow the format nnddhhmmyyyy.ss which is described below

• nn is a two digit month, between 01 to 12
• dd is a two digit day, between 01 and 31, with the regular rules for days according to month and year applying
• hh is two digit hour, using the 24-hour period so it is between 00 and 23
• mm is two digit minute, between 00 and 59
• yyyy is the year; it can be two digit or four digit: your choice. I prefer to use four digit years whenever I can for better clarity and less confusion
• ss is two digit seconds. Notice the period ‘.’ before the ss.

Let’s say you want to set your computer’s new time to December 6, 2007, 22:43:55, then you would use:

sudo date 120622432007.55

It couldn’t be any easier, could it? The source of this information was a good post on Ubuntu Forums (Set time/date via command line).

Change Time Zone

You may update or change your time zone by

tzconfig

This command will guide you through the process of setting a new time zone. You may also choose UTC (GMT) if you want.

If your system does not have tzconfig, you may use something else.

tzselect

This will provide a set of different time zones to choose. If you would like to set the time to UTC, choose the option which says something like ‘none of the above’, or ‘none of these’ or something to this effect. In my case it was option 11. Then it asks for difference from UTC (GMT and GST is also the same thing). I chose GST-0 as the option and it set the time as UTC.

Sync Clock Via NTP

If you want to sync your clock with NTP servers, it is also very easy. Just make sure you have the file ntp.conf file in /etc. How can you check it?

ls /etc/ntp.conf

If you see /etc/ntp.conf as a result, you already have that file. If the ls command gives an error, you do not have it. If so, you may create it yourself.

sudo vim /etc/ntp.conf

This file will be used to automatic synchronization of the clock. I do not know if the client uses this file automatically or one has to configure something first.

Whether you have the file already or not, make sure it has at least the following data

driftfile /var/lib/ntp/ntp.drift
server 0.pool.ntp.org
server 1.pool.ntp.org
server 2.pool.ntp.org
server pool.ntp.org

Here you may replace, add, and/or remove any servers you wish. You will find a list of time servers from the public NTP time server list.

You may manually sync the clock using the following

sudo ntpdate servername

where servername can be any public or private time server. You may always choose the following without hesitation

sudo ntpdate pool.ntp.org

See, it was quite easy. Enabling NTP Services helped me gain this knowledge.

source here

DNS (Domain Name Service) server is a server that translate an IP address into a name that will be easy to remember or do the opposite way.

The administrative job is done in Server side. For client side just set the machine to connect the DNS server.

Before we start, I assume that you are connected to Internet already. For, text editor, you can use any program that you are familiar with. In this sample, I use vim.

The installation is as easy as below:

Step 1. Install the bind9

Open Linux Terminal (Applications>Accessories>Terminal), type: sudo apt-get install bind9

Installation finished.

Read the rest of this entry »