Every running instance of a program is known as a process. The concept of processes is fundamental to the UNIX / Linux operating systems. A process has its own identity in form of a PID or a process ID. This PID for each process is unique across the whole operating system. Also, each process has its own process address space where memory segments like code segment, data segment, stack segment etc are placed. The concept of process is very vast and can be broadly classified into process creation, process execution and process termination.
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If you have ever tried to understand the TCP/IP protocols then you would have definitely stumbled upon the checksum field that is the part of protocol headers like TCP, IP etc.

Have you ever given a thought about things like what exactly is checksum, why is it used and how it is calculated. Well, in this article we will have a brief discussion on the concept of checksum and then we will go into details of how checksum is calculated.
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Q: How do I encrypt my bash shell script on Linux environment? The shell script contains password, and I don’t want others who have execute access to view the shell script and get the password. Is there a way to encrypt my shell script?
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Fast data communication has become the basic need of todays world and Internet has become the heart of the communication ecosystem. Devices like mobile phones (whose purpose is voice communication) are having Internet connectivity and PCs, laptops etc (which are mostly  used for web surfing) are now also being used for voice communication. So we see that technologies are converging or intermixing to provide fast and easy communication.
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Ettercap stands for Ethernet Capture.

Ettercap is a comprehensive suite for man in the middle attacks.

It features sniffing of live connections, content filtering on the fly and many other interesting tricks. It supports active and passive dissection of many protocols and includes many features for network and host analysis.
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There are scenarios in which one would like to know the route which a connection follows. By route here we mean the IP addresses of all the forwarding entities (like routers in between).

Although there is no guarantee that the route will remain same for all the packets of a connection but usually it is same. This route related information can be very handy while debugging network related issues.
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If you try to follow the how to install Apache with SSL article that we discussed a while back, you’ll face an issue during “make” because of version compatibility between Apache 2.4.4 and APR utilities (Apache Portable Runtime Library) that comes with CentOS 6.

We’ve explained in this article how to solve that issue to get the latest Apache working on CentOS or RedHat.
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