Spoofing Multicast packet from another interface.

This is the scenario. I have a working ethernet device eth0 with an IP address 192.168.1.x. There is one more special interface in the system, say if1 which is connected to another network. That network is mainly used for transmitting multicast data. Received multicast data has to be processed by a userland application. Due toContinue reading “Spoofing Multicast packet from another interface.”

Can we avoid Energy Storage

There have been a lot of focus about energy storage these days coupled along with solar and wind. As a coin has two sides, Energy Storage has both pros and cons. Some of the main concerns I could gather are: Prohibitively Expensive Capital Cost: Energy Storage systems are expensive to own. Cheapest solutions like LeadContinue reading “Can we avoid Energy Storage”

Network throughput measurement using netcat

There are many network throughtput and performance measurement tools available. One of the most widely used one is “iperf”. But, I found “netcat” to be a very versatile and fantastic tool to do the same. The only “extra” requirement is to have shell access to both sides, so that netcat could be used. First installContinue reading “Network throughput measurement using netcat”

Kerosene vs. Klean. Lighting up rural India: Cost and Emission Analysis

“Every block of stone has a statue inside it and it is the task of the sculptor to discover it” – Michelangelo As of now, there are around 1.5 Billion people in the world without access to electricity grid, out ot which the share of India would come to around 400 Million people or aroundContinue reading “Kerosene vs. Klean. Lighting up rural India: Cost and Emission Analysis”

Problems of Lunar Solar Power

There have been a lot of proposals about having Solar Power Stations on Moon. The plan is to create a belt of solar modules around 11000km equator. The power will be taken to Earth using Microwave beams. After going through some of their ideas, I thought it was not an idea at all. Some ofContinue reading “Problems of Lunar Solar Power”

Taking OpenEmbedded SRC_URI from environment variable

OpenEmbedded uses SRC_URI to determine where the source code is taken from. For many projects it would be convenient to use source code from local repository due to many reasons, in order to support that, it is possible to use file URI as ‘file://’ For example, SRC_URI=”file:///path/to/local_repo/whatever_project” This can create problem because it is notContinue reading “Taking OpenEmbedded SRC_URI from environment variable”

Creating a Minimal Kernel Development Setup using KVM/Qemu

I wanted to setup a Linux kernel development system and the best choice I found was using KVM/Qemu. Both KVM and Qemu use the same virtual hardware specification, but KVM could give near native performance using special processor instructions. Since both of them use the same virtual hardware, the same virtual disk image could beContinue reading “Creating a Minimal Kernel Development Setup using KVM/Qemu”

Basic Mathematics from shell command line

It is possible to do a lot of calculations from command shell itself without using any spreadsheet applications or scripting languages like perl or python. What we require is simple un*x applications like, bc, xargs, awk etc. To sum a list of numbers There are many different ways to do that, but the best wayContinue reading “Basic Mathematics from shell command line”