ArchiveMarch 2019

What is SNMP


SNMP is a communications protocol that allows remote monitoring and remote management of devices running on an Ethernet network.  Remote management requires: 1. A communication protocol (SNMP protocol); 2. Management Information Bases, MIB. 3. An SNMP agent. 4. An SNMP Manager. The SNMP protocol runs at the application level of the TCP/IP protocols stack and is used by managers and agents to...

502 Bad Gateway


We usually get this error when we try to access a web page and the first web server is not receiving a response from another web server along with the route on which the data passes. Often this signifies a problem for the website and most of the time we can’t do anything about it, but there are exceptions when the problem can be from the network configuration or our own device. A 502 Bad...

Apache versus nginx


Apache Apache is an open source HTTP server which is developed by an open community of programmers working together under the Apache Software Foundation. The application is available for a wide variety of operating systems including Unix, FreeBSD, Linux, Solaris, Novell NetWare, Mac OS X, Microsoft Windows. The Apache server was always a free and open source software, sometimes being regarded as...

What is cURL


cURL is software that mostly works as a command line utility and library used to transfer data on a variety of protocols. The largest number of commercial users of Curl are in Japan and other Asian countries, but Curl is fairly accessible in the West. Curl Headquarters is located in Cambridge, Massachusetts, and the Sumisho Computer Systems Corp wholly owns it. cURL supports a wide variety of...

What is TightVNC


A free and open source software, TightVNC is an app that connects remotely, via the internet, two or more computers. The software consists of two apps: the first one is the TightVNC server and we have to install it on the receiving computer or the remote one; the second app is the TightVNC viewer and must be installed on the computer from which we will connect, or the local machine. Through a...

What is PostgreSQL


PostgreSQL is a relational database system. It is available for free under an open source BSD license. A company does not control PostgreSQL, but it bases its development on a globally distributed community, as well on several developers. PostgreSQL allows the use of procedural languages ​​to execute code blocks directly in the database server. It can be used to create user-defined functions...

What is GIT


Git is a revision system running on most platforms, including Linux, POSIX, Windows and OS X. Like Mercurial, Git is a distributed system and does not maintain a common database. It is used in large development teams where team members are somewhat independent and are spread over a large geographical area. Git is developed and maintained by Junio ​​Hamano and is licensed as free software under...

What is Grep


Grep is a UNIX text search command. The name comes from the first letters of “global/regular expression/print”, which is a series of commands for editors such as ed. The “grep” command searches for files in or standard inputs that correspond to a regular expression and writes them to the standard output. There are countless implementations and variations of the grep...



The “Hello, World!” is the first, simple and complete, program for beginners as well as a good program for testing systems and programming environments. “Hello, World!” is the basic syntax of programming languages. This tutorial will help you write the “Hello, World” program in Python 3 on different programming platforms. We need Python 3 and an editor. An...

How does IPtables work


There are two types of firewalls: 1. Filtering firewalls – which blocks specific packages. 2. Proxy Servers – Establishing network connections to the Internet from computers inside the LAN. Linux kernels have had packet filters since the 1.1 series. The first generation of packet filters, based on ipfw, was ported by Alan Cox in 1994. Jos Vos and others upgraded it for the 2.0...

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