Category Archives: Computer Networks

How I use raspberry pi at my home to block advertisements on all devices and load webpages fast!

My father is not an avid internet user and he doesn’t understand or care for things like adblocker. I did install adblocker on his PC but many news sites and blog don’t allow you access if you have adblocker enabled. He keeps calling me all the time with problems that he is unable to access a webpage so I just disabled adblocker for him. That came with different baggage of problems altogether. He kept complaining me about the junk and popups he gets on different websites and I had to somehow fix this. So I decided to fix the problem for all devices at my home with a very small hack. After finishing my setup I thought of putting up the setup on my blog. So here’s how it goes. Continue reading

Software Defined Networking. What is it and why do we need it?

Over the past few decades computing has advanced very fast but networking has not kept pace with it. Traditional networks have become very closed and proprietary. The devices like routers and switches which run the Internet have become very complex because of the overly complex distributed protocols run by them. Continue reading

Save yourself from dictionary attack.

HI everyone,

Recently a DDOS attack was launched on DNS Server of Dyn[ref]https://www.theguardian.com/technology/2016/oct/26/ddos-attack-dyn-mirai-botnet[/ref]. It brought many websites down[ref]http://www.cnbc.com/2016/10/21/major-websites-across-east-coast-knocked-out-in-apparent-ddos-attack.html[/ref]

In the meantime, a friend of mine was also attacked and his account was also used to launch a DDOS attack. He was hacked on 19th October and the large scale attack on DYN servers were launched on 21st October. Continue reading

Getting started with nmap

Nmap (“Network Mapper”) is an open source tool for network exploration and security auditing. It was designed to rapidly scan large networks. Nmap uses raw IP packets in novel ways to determine what hosts are available on the network, what services those hosts are offering, what operating systems they are running, what type of packet filters/firewalls are in use, and dozens of other characteristics.

Recently I had to demonstrate a security tool for my network security course and I decided to use nmap.

I am not going to write everything but I will mostly link you to many articles that I considered. Actually in present scenario there is a wealth of knowledge available related to nmap but if you do a google search to learn it then you will get lost in that ocean.
I have compiled a well organised collection of articles which I followed in a sequence to learn nmap and I have also explained some basics that you need to know to understand nmap and how it works. Continue reading

Fastest way to get started with OpenDaylight

What is OpenDaylight?

As per wikipedia:

The OpenDaylight Project is a collaborative open source project hosted by The Linux Foundation. The goal of the project is to accelerate the adoption of software-defined networking (SDN) and create a solid foundation for Network Functions Virtualization (NFV). The software is written in Java.

Sometimes installation of these tools can get a little difficult since they are not very well documented.

Easiest way to getting started with OpenDaylight Continue reading