Author Archives: Qasim Mehmood

An exclusive interview of Mr. Babar Zahoor, an Open Source Evangelist and Founder Open source Foundation of Pakistan, at Whogothacked.

An Exclusive Interview with Babar Zahoor Founder Open source Foundation Pakistan – for who got hacked by Mansab Ali Chohadry, Founder Who Got hacked. Mr. Babar Zahoor is an Open Source Evangelist and  Founder Open source Foundation Pakistan, having a lot of experience in the field of  Open Source Technologies and Linux Operating Systems. Continue reading

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Ntopng How to install Ntopng Network Traffic Monitoring Tool



Ntopng is a very useful network traffic monitoring system, its a monitoring tool with detailed graphs and  flows. Its interface having a number of view options of network traffic, including the top flow talkers, top hosts (Send/Receive) data, application protocols in use, top flow senders data live. Each and every node’s active flow can be viewed using the ntopng.

For reference

To Install Ntopng, the following steps are followed, first of all we need to upgrade the repository files, create the following file to start up for installation:

# vi /etc/yum.repos.d/ntop.repo
name=ntop packages

Now create the file in “/etc/yum.repos.d/epel.repo extra repositories”

# vi /etc/yum.repos.d/epel.repo
name=Extra Packages for Enterprise Linux 6 -

name=Extra Packages for Enterprise Linux 6 -  - Debug

name=Extra Packages for Enterprise Linux 6 -  - Source

Now do the following:
To clean all yum data

yum clean all

To update the repositories and all installed packages following command is used.

yum update -y

Redis and Hiredis are the required packages for the Ntopng installation, so need to install it before going to install ntopng

yum install redis hiredis

if there will be problem for installation of redis or hiredis, do install the following rpm:

rpm -ivh

Now install the pf_ring

yum install pfring

after successful installation of all the above mentioned packages, install ntopng with its packages

yum install ntopng ntopng-data nbox

Now edit the ntopng configuration file and make the following changes.

vi /etc/ntopng/ntopng.conf 

Now edit the ntopng start “ntopng.start” file and make following changes.

vi /etc/ntopng/start.conf
--local-networks ## give your local IP Ranges here.
--interface 0

Now run the following commands to start the services of redis and ntopng.

service redis start 
service ntopng start

Al Hamdu Lillah we have done it.
The Following graphs will be displayed on completion of installation process and configuration of ntopng.


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DHCP Server How to Install DHCP Server on CentOS

DHCP stands for Dynamic Host Configuration Protocol. This is a standardized network protocol and is used to automatically assign IP Address to computers on network. It is configured in a Client-Server Environment. DHCP server is the one that assigning IP Addresses to client computers on the network. Each client is assigned a unique IP Address. DHCP server has a number of IP Addresses available in it’s pool, according to requirement of network. Through the DHCP Server IP Addresses are assigned to clients automatically, whenever a computer joins-in through wired or wireless network.

Installation of DHCP Server

Installation of DHCP Server

Best Practice for the deployment of DHCP Server in your Network:

  • Configure the DNS (Domain Name Server) in your network. Installation and configuration of DNS is given at “How to Install DNS Server
  • Assign a static IP address to your DHCP server

Installation of DHCP Server.

# yum install dhcp* -y
# vi /etc/dhcpd.conf
# cat /usr/share/doc/dhcp-4.1.1/dhcpd.conf.sample
# cp /usr/share/doc/dhcp-4.1.1/dhcpd.conf.sample /etc/dhcpd.conf

Edit the /etc/dhcpd/dhcpd.conf file to reflect your desired configuration.

# dhcpd.conf
# Sample configuration file for ISC dhcpd
# option definitions common to all supported networks...
option domain-name "";                      # Change with your DomainName
option domain-name-servers,;         # Change with your DNS IP Addresses 

default-lease-time 600;                                                  # Change with the desired lease time
max-lease-time 7200;                                                     # Change with the maximum desired lease time
# Use this to enble / disable dynamic dns updates globally.
#ddns-update-style none;
# If this DHCP server is the official DHCP server for the local
# network, the authoritative directive should be uncommented.
# Use this to send dhcp log messages to a different log file (you also
# have to hack syslog.conf to complete the redirection).
log-facility local7;                                                     # Option to enable logging to /var/log/messages
# No service will be given on this subnet, but declaring it helps the
# DHCP server to understand the network topology.
#subnet netmask {
# This is a very basic subnet declaration.
subnet netmask   {        # Change with your network IP and Netmask
range;                                 # IP Range to serve - our case from to
option routers;                                                    # Change with IP Address of Gateway
# This declaration allows BOOTP clients to get dynamic addresses,
# which we don't really recommend.
# subnet netmask {
#  range dynamic-bootp;
#  option broadcast-address;
#  option routers;
# A slightly different configuration for an internal subnet.
# subnet netmask {
#  range;
#  option domain-name-servers;
#  option domain-name "";
#  option routers;
#  option broadcast-address;
#  default-lease-time 600;
#  max-lease-time 7200;
# Hosts which require special configuration options can be listed in
# host statements.   If no address is specified, the address will be
# allocated dynamically (if possible), but the host-specific information
# will still come from the host declaration.
#host passacaglia {
#  hardware ethernet 0:0:c0:5d:bd:95;
#  filename "vmunix.passacaglia";
#  server-name "";
# Fixed IP addresses can also be specified for hosts.   These addresses
# should not also be listed as being available for dynamic assignment.
# Hosts for which fixed IP addresses have been specified can boot using
# BOOTP or DHCP.   Hosts for which no fixed address is specified can only
# be booted with DHCP, unless there is an address range on the subnet
# to which a BOOTP client is connected which has the dynamic-bootp flag
# set.
host foo2 {                                                                                     # Change with Hostname of host to assign fixed IP Address
hardware ethernet 08:00:27:6B:06:7E;                    # Change with fixed IP host MAC Address
fixed-address;                                                  # Change with the desired IP Address you want to assign to host
# You can declare a class of clients and then do address allocation
# based on that.   The example below shows a case where all clients
# in a certain class get addresses on the 10.17.224/24 subnet, and all
# other clients get addresses on the 10.0.29/24 subnet.
#class "foo" {
#  match if substring (option vendor-class-identifier, 0, 4) = "SUNW";
#shared-network 224-29 {
#  subnet netmask {
#    option routers;
#  }
#  subnet netmask {
#    option routers;
#  }
#  pool {
#    allow members of "foo";
#    range;
#  }
#  pool {
#    deny members of "foo";
#    range;
#  }

now close “dhcpd.conf” file.

Start dhcpd service

# service dhcpd start

Starting dhcpd.... [OK}
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NTop – How to Install Ntop Network Traffic Monitoring Tool in Linux by Qasim Mehmood


Ntop is a web-based Graphical, Network Traffic Monitoring Tool, NTop shows network usage on real time, a web browser can be used to manage and navigate through Ntop traffic information to better understand network status. Among other things, Ntop monitors, report hosts traffic and supports the following  protocols:

  • TCP
  • UDP
  • ICMP
  • SNMP
  • (R)ARP
  • IPX
  • DLC
  • Decnet
  • HTTP
  • Netbios

The  installation of Ntop is a pretty simple task. It can easily installed on linux 5.x/6.x using yum command, but first you need to install the EPEL Repository (Extra Packages for Enterprise Linux Repository), applicable to your Operating System architecture 32bit or 64bit (if already not installed) by using the following commands (make sure, you must be root user):
Install EPEL RPM for CentOS 6.x

# wget
# rpm -ivh epel-release-6-8.noarch.rpm


# wget
# rpm -ivh epel-release-6-8.noarch.rpm

Install EPEL RPM for CentOS 5.x

# wget
# rpm -ivh epel-release-5-4.noarch.rpm


# wget
# rpm -ivh epel-release-5-4.noarch.rpm

Once the repository is installed, all you need to do to install Ntop in CentOS using the following commands:
Install NTop

# yum install ntop
# ntop

here  the ntop monitoring logs will start-up on command prompt and it will ask for the admin password, set the password of “admin” user for future use. After the installation of Ntop is complete, now open the web browser to start monitoring using the NTop as mentioned below:




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HTop – CPU, Memory & Process Monitoring Utility in Linux by Qasim Mehmood


Htop is a text-mode, interactive process viewer for Linux run via console/ssh, and to install htop on Linux is a pretty simple task. Among other things, htop allows you the following:

  • Quickly view key performance statistics such as CPU(multi-core layout), Memory and Swap usage Details.
  • Scroll the process list vertically and horizontally to see all processes and complete command lines.
  • Kill processes by selection rather than entering process number, use mouse to select list items.
  • PuTTY (the Telnet and SSH client) can be used for the interface at client.

How to install Htop

You can easily install htop on CentOS 6.x using yum, but first you need to install the rpmforge package repository applicable to your architecture 32bit or 64bit (if already not installed) by using the following commands:

Install RPM for CentOS 6.x


rpm -Uhv rpmforge-release*.rf.i386.rpm



rpm -Uhv rpmforge-release*.rf.x86_64.rpm

Once the repository is installed, all you need to do to install htop in CentOS is run the following:

yum install htop

Now run the following command at command prompt or in PuTTy to start htop processes viewer.


After the installation of Htop, you can view the manual and other utilities of Htop, with the following commands.

[qasim@server ]# man htop                                           To view manual of htop, having complete details.

[qasim@server ]#htop -h                                                 To view different options/plug-ins.

[qasim@server ]#htop -u username                            To view the active user’s currently running processes information.

[qasim@server ]#htop -u qasim                                    To view the qasim’s currently running processes information.

[qasim@server ]#htop -u root                                       To view the root’s currently running processes information


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