Convert .p12 bundle to server certificate and key files

Seperate Private Key and Certificate file

#Generate certificates bundle file

openssl pkcs12 -nokeys -in server-cert-key-bundle.p12 -out server-ca-cert-bundle.pem

#Generate server key file.

openssl pkcs12 -nocerts -nodes -in server-cert-key-bundle.p12 -out server.key

Convert a PKCS#12 file (.pfx .p12) containing a private key and certificates to PEM

openssl pkcs12 -in keyStore.pfx -out keyStore.pem -nodes

Create a .pfx/.p12 certificate file using OpenSSL

openssl pkcs12 -export -out certificate.pfx -inkey privateKey.key -in certificate.crt



Softether on VPS Using Local Bridge

Problem on SecureNAT

SecureNAT is a fairly simple way to setup Softether. You don’t need a lot of sysadmin skill and network understanding in order to get Softether up and running.

The problem is SecureNAT is a bit SLOW. I will show a comparison at the end of this article.

We can boost the performance using a local bridge.

Softether using local bridge

To start with you need Softether installed and setup. You can follow the guide on Softether on VPS

Just skip the last step “Enable the Virtual NAT”

Local bridge Setup

Network setup

  • VPN Server IP:
  • VPN Client IP Range:
  • Tap Device name: tap_soft

From here we go to the “Local Bridge Setting”

Continue reading “Softether on VPS Using Local Bridge” »


Customizing Jitsi Meet

Edit Logo Image:

In your jitsi-meet deployment, probably in /usr/share/jitsi-meet/images the image file will exist that you can override with your own.

Update Link on Logo:

You can edit:
Path: /usr/share/jitsi-meet
File: interface_config.js

Change texts of Welcome/Home Page: Continue reading “Customizing Jitsi Meet” »


Build a Public NTP Server

Install NTPd and Configure NTP server for time adjustment.

[root@dlp ~]# yum -y install ntp
[root@dlp ~]# vi /etc/ntp.conf
# line 18: add the network range you allow to receive requests publicly
restrict mask nomodify notrap

# change servers for synchronization

#server iburst
#server iburst
#server iburst
#server iburst
server iburst
server iburst
[root@dlp ~]# systemctl start ntpd
[root@dlp ~]# systemctl enable ntpd

If Firewalld is running, allow NTP service. NTP uses 123/UDP. Continue reading “Build a Public NTP Server” »


Large Database Import Progress Using PV

PV can report progress for large data imports. In this example I will use a large (7 G) install on Ubuntu. First, download PV (

sudo apt-get install pv

A traditional mysql import may be formatted as:

mysql -u USER -p DATABASE_NAME < DUMP.mysql

but to leverage PV, pass the dump file ,then pipe the mysql command specifying the database with -D flag:

pv DUMP.mysql | mysql -u USER -p -D DATABASE_NAME

Your import will report progress and an ETA 🙂


Installing Manageengine Opmanager 12 standar/pro edition on Linux Centos 7

Lately for a project needed to install opmanager for a specific client. The installation is quite straight forward on a fresh installation of Centos 7 Box. Assuming you already have a linux installaiton file (ended with .bin) file. So here it goes-

Installing OpManager on Linux using Console mode / Silent mode
This is a quick walk-through of the console mode installation of OpManager on a Linux box – an easy thing to do if you are working on a Windows box and want to install on a remote Linux system.


To begin with, make sure you have downloaded the binary for Linux. (

Steps to install

Step 1: Execute the binary with administrator privileges (sudo) and -i console option.

Continue reading “Installing Manageengine Opmanager 12 standar/pro edition on Linux Centos 7” »


বাবা ভাঙ্গার যত ভবিষ্যদ্বাণী

কে এই বাবা ভাঙ্গা?
বুলগেরিয়ায় জন্ম নেয়া বাবা ভাঙ্গা তাঁর জীবনে যত ভবিষ্যদ্বাণী করেছেন তার ৮৫ শতাংশই মিলে গেছে৷ ১৯৯৬ সালে ৮৫ বছর বয়সে তিনি মারা যান৷ কথিত আছে, রহস্যময় এক ঝড় তরুণী বাবা ভাঙ্গাকে উড়িয়ে নিয়ে এক মাঠে ফেলে দেয়৷ বেশ কদিন পর পরিবারের লোকজন তাকে খুঁজে পায়৷ কিন্তু বালু আর ময়লার কারণে ব্যথায় তিনি চোখ খুলতে পারছিলেন না৷ পরে অন্ধ হয়ে যান তিনি৷ Continue reading “বাবা ভাঙ্গার যত ভবিষ্যদ্বাণী” »


Let’s Encrypt for cPanel Installation


Let’s Encrypt for cPanel Installation using Installing the cPanel Plugin

Log into your SSH client at root level, then add the Let’s Encrypt repository with the following command:

cd /etc/yum.repos.d/ && wget

Next, install the plugin for cPanel with line below and yum:

yum -y install letsencrypt-cpanel

The installation process usually takes about a minute. If all goes well and the installation was successful, a test should run automatically. If it renders similar messages as the example below, you’re good to go:

le-cp self-test
[SELF-TEST] Can read config ............ SUCCESS.
[SELF-TEST] Can connect to daemon and check licence ............ SUCCESS.
[SELF-TEST] Can connect to Lets Encrypt ............ SUCCESS.
[SELF-TEST] Can talk to WHM API ............ SUCCESS.
[SELF-TEST] Can talk to plugin RPC ............ SUCCESS.

You can log in to your cPanel account and install your first SSL certificate.

Installing a Certificate
Once you’re logged into cPanel, you should see a Let’s Encrypt for cPanel button under Security. Click on it to access your active domains list to install a certificate.

Continue reading “Let’s Encrypt for cPanel Installation” »


Extend/Reduce LVM’s (Logical Volume Management) in Linux

My Server Setup – Requirements

  1. Operating System – CentOS 6.5 with LVM Installation
  2. Server IP –

How to Extend Volume Group and Reduce Logical Volume

Logical Volume Extending

Currently, we have One PV, VG and 2 LV. Let’s list them one by one using following commands.

# pvs
# vgs
# lvs

Logical Volume Extending

Logical Volume Extending

Continue reading “Extend/Reduce LVM’s (Logical Volume Management) in Linux” »


How to Add Additional Physical NICs to XenServer

From the XenServer Command Line Interface (CLI), issue the following command:

xe pif-list

Press Enter.

Note: If you have more than one XenServer in the pool, you must issue the xe host-list command to list all the XenServer hosts and write down the Universally Unique Identifier (UUID) of the host that you added the new NIC, then issue command xe pif-list host-uuid=[uuid of the XenServer host]

The preceding command lists all the physical NICs of that XenServer. If you do not see the additional NIC, you must scan for new physical interface(s) on a XenServer and issue this command:

xe pif-scan host-uuid=[uuid of the XenServer host]

Press Enter. Continue reading “How to Add Additional Physical NICs to XenServer” »