Before go to this post you need to view How to configure
LDAP server and client configuration click here...
Showing posts with label Centos. Show all posts
Showing posts with label Centos. Show all posts
Wednesday, March 13, 2013
Wednesday, February 13, 2013
Install and Setup Zimbra in CentOS
Zimbra is a suite of tools for
Unix/Linux/MacOS systems, which includes a secure mail server, web mail,
anti-spam/anti-virus controls, a Web management interface, integrated
calendaring, mobile device sync, and more. In many ways, Zimbra is the Unix
equivalent to Microsoft Exchang...
Thursday, October 18, 2012
Linux Hotplug a CPU
How do
I hotplug a CPU on a running Linux system? I would like to dynamically enable
or disable a CPU on a running system?
Linux kernel does supports cpu-hotplug mechanism. You
can enable or disable CPU without a system reboot....
Content Filter by Using Squid, Squid guard / Dansguardian at Free-of-Cost
INTRODUCTION
The post fully
deals with several parts of internet based utilities and restrictions that are
mainly used in IT industry like to limit the web access for some users to a list
of accepted/well known web servers and/or URLs...
Wednesday, October 3, 2012
Controlling Web Access With SQUID
This summary is not available. Please
click here to view the pos...
The Linux Boot Process in Detail
1.
When a PC is booted it starts running a BIOS program which is a memory resident
program on an EEPROM integrated circuit.
BIOS –
Basic Input Output
of the System
EEPROM -
Electrically
Erasable Programmable Read-Only
Memory
...
Thursday, September 27, 2012
Sudo Full Practical Session
Introduction
Before we proceed, it would be best
to cover some basic user administration topics that will be very useful in
later chapters. Adding Users
One of the most important
activities in administering a Linux box is the addition of users. Here you'll
find some simple examples to provide a...
Wednesday, September 26, 2012
Using chkconfig to Start Daemons at Each runlevel
As stated earlier, the chkconfig command can be used to adjust
which applications start at each runlevel. You can use this command with the
--list switch to get a full listing of packages listed in /etc/init.d and the
runlevels at which they will be on or off:
...
Friday, September 21, 2012
Linux / Unix Commands For Connecting To The Serial Console
Most embedded Linux /
BSD systems such as routers, servers and nas devices comes with console
interface (serial port with RS-232). BIOS can use this, and after boot BIOS
screen I/O is redirected so that you can use the device. RS-232 is also used
for communicating to headless server, where no monitor or keyboard is
installed, during boot when operating system is not running yet and therefore
no network connection is possible. You need...
How To Check and Use Serial Ports Under Linux
How do I check and configure serial ports under
Linux for various purposes such as modem, connecting null modems or connect a
dumb terminal?
Linux offers various tools. Linux uses ttySx for a
serial port device name. For example, COM1 (DOS/Windows name) is ttyS0, COM2 is
ttyS1 and so on.
Task:
Display Detected System's Serial Support
Simple
run dmesg command
...
Wednesday, September 12, 2012
Allow A Normal User To Run Commands As root Under Linux / UNIX Operating Systems
From my mail bag:
I would like to run
few commands such as stop or start web server as a root user. How do I allow a
normal user to run these commands as root?
You need to use the sudo command which is use to execute a command as another
user. It allows a permitted user to execute a command as the superuser or
another user, as specified in the /etc/sudoers (config file that defines or
list of who can run what) file. The sudo command...
Wednesday, September 5, 2012
Linux log files location and how do I view logs files?
Q. I am new to Linux and I would like to know
where are the log files located under Debian or Cento OS Linux server? How do I
open or view log files?
Ans. Almost all logfiles
are located under /var/log directory (and subdirectory). You can change to this
directory using cd command but you need to be the root user. You can use less,
more, cat or tail command to see the logs.
Go to /var/logs
directory:
...
How do I rotate log files?
Q. How do I rotate log files under Linux operating system?
A. You need use tool called logrotate, which is
designed to ease administration of systems that generate large numbers of log
files. It allows automatic rotation, compression, removal, and mailing of log
files.
Each
log file may be handled daily, weekly, monthly, or when it grows too large.
With this tool you keep logs longer with less disk space.
Default configuration...
Redhat Enterprise Linux 5 / CentOS 5 monitor and track TCP connections on the network
Q. How do I track and monitor connection for eth1 public
network interface under Redhat Enterprise Linux (RHEL) 5 server?
Ans.You can use netstat
command or tcptrack command. Both command can show established TCP connection
and provides the ability to monitor the same....
BASIC LDAP CONFIGURATION For RHEL / Centos / Fedora
INTRO: LDAP stands for Lightweight Directory Access Protocol. It is used as
centralized data (or
Directory)
server (not database server)
for various purposes.
There
is a difference between Directory server
and a Database server.
In
Directory server
the data is read more frequently than it is
written.
In
Database server
the data is written more frequently than it is
read.
Here
we shall see how LDAP is
used for creating centralized...
Monday, September 3, 2012
Linux: Iptables Examples For New SysAdmins Part -->3
Before see this post please read my
previous post (Linux: Iptables Examples For New SysAdmins Part -->2)
#12: Log and Drop
Packets
Type the following to
log and block IP spoofing on public interface called eth1
# iptables -A INPUT -i eth1 -s 10.0.0.0/8 -j LOG --log-prefix "IP_SPOOF A:
# iptables -A INPUT -i eth1 -s 10.0.0.0/8 -j DROP
...
Linux: Iptables Examples For New SysAdmins Part -->2
Before see this post please read my previous post (Linux: Iptables Examples For New SysAdmins Part -->1)
#3: Delete Firewall Rules
To display line number
along with other information for existing rules, enter:
# iptables -L INPUT -n --line-numbers
# iptables -L OUTPUT -n --line-numbers
# iptables...
Linux: Iptables Examples For New SysAdmins Part -->1
Linux comes with a host based firewall called
Netfilter. According to the official project site:
netfilter is a set of hooks inside the Linux
kernel that allows kernel modules to register callback functions with the
network stack. A registered callback function is then called back for every
packet that traverses the respective hook within the network stack.
This
Linux based firewall is controlled by the program called iptables to...
Redhat / CentOS Iptables Firewall Configuration
H
ow do I configure a
host-based firewall called Netfilter (iptables) under CentOS / RHEL / Fedora /
Redhat Enterprise Linux?
Icon reference for Firewall
Netfilter is a host-based firewall for Linux
operating systems. It is included as part of the Linux distribution and it is
activated...
What is sysctl.conf in Linux
sysctl is an interface that allows you to make
changes to a running Linux kernel. With /etc/sysctl.conf you can configure
various Linux networking and system settings such as:
1.
Limit network-transmitted configuration for IPv4
2.
Limit network-transmitted configuration for IPv6
3.
Turn on execshield protection
4.
Prevent...
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