NMAP Security Scanner on Linux

First of all, you should get the “nmap” package installed in your system.

On CentOS

yum install nmap

On Debian

apt-get install nmap

On Ubuntu

sudo apt-get install nmap

NMAP Commands:

sudo nmap -sS [IP address] or [website address]
sudo nmap -O --osscan-guess [IP address] or [website address]
sudo nmap -vv [IP address] or [website address]
sudo nmap -sV [IP address] or [website address]

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PEN: HTTP Load Balancer

This is performed on a CentOS 6.x 64 bit machine

Install pen which is lightweight simple Load Balancing software.

It is TCP protocol based, so it’s possible to balance not only HTTP but SMTP, FTP, LDAP and so on. This example is based on the environment like follows.


Configure Pen to load balance to Backend#1, Backend#2, Backend#3 web servers. Continue reading “PEN: HTTP Load Balancer” »


User management in Nebula

Adding and Deleting Users

User accounts within the OpenNebula system are managed by oneadmin with the oneuser create and oneuser delete commands. This section will show you how to create the different account types supported in OpenNebula


Administrators can be easily added to the system like this:

$ oneuser create otheradmin password
ID: 2
$ oneuser chgrp otheradmin oneadmin

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Reset Oneadmin password

In case of lost password you can use another user in oneadmin group to change the lost password:

$ oneuser passwd --sha1 oneadmin 'newpassword'


  • Change the password directly in the database:
  • Stop OpenNebula daemons (this is needed as some data is cached).
  • Connect to the database and get the body of oneadmin user:
  • select body from user_pool where name=’oneadmin’;

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How to login OpenNebula VM using Putty by public key exchanging

Generating OpenSSH-compatible Keys for Use with PuTTY

To generate a set of RSA keys with PuTTYgen:

  1. Start the PuTTYgen utility, by double-clicking on its .exe file;
  2. For Type of key to generate, select SSH-2 RSA;
  3. In the Number of bits in a generated key field, specify either 2048 or 4096 (increasing the bits makes it harder to crack the key by brute-force methods);
  4. Click the Generate button;
  5. Move your mouse pointer around in the blank area of the Key section, below the progress bar (to generate some randomness) until the progress bar is full;
  6. A private/ public key pair has now been generated;
  7. In the Key comment field, enter any comment you’d like, to help you identify this key pair, later (e.g. your e-mail address; home; office; etc.) — the key comment is particularly useful in the event you end up creating more than one key pair;
  8. Optional: Type a passphrase in the Key passphrase field & re-type the same passphrase in the Confirm passphrase field (if you would like to use your keys for automated processes, however, you should not create a passphrase);
  9. Click the Save public key button & choose whatever filename you’d like (some users create a folder in their computer named my_keys);
  10. Click the Save private key button & choose whatever filename you’d like (you can save it in the same location as the public key, but it should be a location that only you can access and that you will NOT lose! If you lose your keys and have disabled username/password logins, you will no longer be able log in!);
  11. Right-click in the text field labeled Public key for pasting into OpenSSH authorized_keys file and choose Select All;
  12. Right-click again in the same text field and choose Copy.

NOTE: PuTTY and OpenSSH use different formats for public SSH keys. If the SSH Key you copied starts with “—- BEGIN SSH2 PUBLIC KEY …”, it is in the wrong format. Be sure to follow the instructions carefully. Your key should start with “ssh-rsa AAAA ….” Continue reading “How to login OpenNebula VM using Putty by public key exchanging” »


Branding the Sunstone Portal

You can easily add you logos to the login and main screens by updating the logo: attribute as follows:

The login screen is defined in the


The logo of the main UI screen is defined for each view in the view file.

Find more on:



Mustafizur stars in landmark series win- Bangladesh v India, 2nd ODI, Mirpur

216075Bangladesh 200 for 4 (Shakib 51*, Ashwin 1-32) beat India 200 in 45 overs (Dhawan 53, Mustafizur 6-43) by six wickets (D/L method)

Mustafizur Rahman was the hero in Mirpur again, (off)cutting through India’s batting with a six-wicket haul to add to his five-for on ODI debut, and launching Bangladesh to their first ever bilateral series win against India. Mustafizur’s 6 for 43, the second best figures by a Bangladesh bowler in ODIs, skittled India for 200, before Shakib Al Hasan steered the chase with a busy fifty, his second on the trot.

With this six-wicket win, Bangladesh also cemented their place in the 2017 Champions Trophy. An overjoyed Mashrafe Mortaza, who has been a part of each of Bangladesh’s five victories against India, toasted his team’s “big achievement”.

Why Bangladesh’s target was 200
When the rains came, India were already eight wickets down after 43.5 overs. Because the game was revised to 47 overs per side, India lost out on some batting opportunity, but that loss was minimal as they were already eight down at the time of the interruption. According to the DLS calculations, the batting resources denied to Bangladesh at the start of their innings, compared to what they would have had in a full 50-over innings, was marginally more than the resources India lost out on.

Continue reading “Mustafizur stars in landmark series win- Bangladesh v India, 2nd ODI, Mirpur” »