I'm back....

Hi guys, get involved much in my new job.So, unable to find time for blog update. I have learned a beautiful tech called... MVC3... soon i will update the techniques in MVC3.

Biggest Cyberattack in History

A cyberattack originally targeting a single company is now being described by experts as one of the biggest Distributed Denial of Service (DDoS) attacks in Internet history. The assault, which recently began impacting elements of the Internet's physical infrastructure, has been dragging down Internet speeds in Europe — but what makes this type of attack different from all other attacks?

First, some background: The attacks originally targeted a European anti-spam company called Spamhaus, which blacklists what it considers sources of email spam and sells those blacklists to Internet Service Providers. The attack began early last week as waves of large but typicalDDoS assaults shortly after Spamhaus blacklisted Cyberbunker, a controversial web hosting company. Cyberbunker has not directly taken responsibility for the attacks against Spamhaus.

In a common DDoS attack, hackers use thousands of computers to send bogus traffic at a particular server in the hopes of overloading it. The computers involved in DDoS attacks have often been previously infected with malware that gave a hacker control of the machine without the legitimate owner's knowledge. Hackers use malware (often sent via email spam) to amass large networks of infected computers, called "botnets," for DDoS operations and other purposes.

Spamhaus contracted with security firm CloudFlare to help mitigate the attacks soon after they began. CloudFlare has been defending Spamhaus by spreading the attacks across multiple data centers, a technique that can keep a website online even if it's hit by the maximum amount of traffic a typical DDoS can generate.

"Usually these DDoS attacks have kind of a natural cap in their size, which is around 100 gigabits per second," CloudFlare CEO Matthew Prince told Mashable before explaining the limitation in typical DDoS attack size is due to routing hardware limitations.

These attacks, however, have evolved into a complex and ferocious beast, pointing up to 300 gigabits per second at an expanding list of targets. How?

After the hackers realized they couldn't knock Spamhaus offline while it was protected by CloudFlare, they chose a different tactic: targeting CloudFlare's own network providers by exploiting a known fault in the Domain Name System (DNS), a key piece of Internet infrastructure.

"The interesting thing is they stopped going after us directly and they started going after all of the steps upstream from us," said Prince. "Going after our immediate transit providers, then going after their transit providers."

DNS essentially turns what humans type into an address bar ("www.mashable.com") to the desired website's IP address and helps to deliver the desired Internet content to a user's computer. An essential element of the DNS system are DNS resolvers — 21.7 million of which are open and able to be found and manipulated by hackers.

"The attack works by the attacker spoofing the victim's IP address, sending a request to an open resolver and that resolver reflecting back a much larger response [to the victim], which then amplifies the attack," said Prince. A detailed technical explanation is available on CloudFlare's blog.

Because DNS resolvers are connected to large pipes with plenty of bandwidth to point at a target, hackers can manipulate them to amplify standard DDoS attacks from a maximum of about 100 gigabits per second to the neighborhood of 300 gigabits per second.

Prince told Mashable these attacks have been "certainly the largest attacks we've seen."

"And we've seen what we thought were some big attacks," he added. Kaspersky Labs, a leading security research group, called it "one of the largest DDoS operations to date."

Internet speeds around the world can be impacted by such large-scale DNS amplified DDoS attacks because the Internet relies on DNS to work — major interference with DNS can have consequences for services not necessarily being directly targeted by such an attack.

What can be done about preventing these specialized DDoS attacks? First, said Prince, Internet Service Providers should implement technologies that prevent hackers from spoofing victims' IP addresses. Second, network administrators need to close any and all open DNS resolvers running on their network.

"Anyone that's running a network needs to go to openresolverproject.org, type in the IP addresses of their network and see if they're running an open resolver on their network," said Prince. "Because if they are, they're being used by criminals in order to launch attacks online. And it's incumbent on anyone running a network to make sure they are not wittingly aiding in the destruction of the Internet."

Google’s Making Moves to Kill the Password

Passwords are long and complicated and hard to remember. And that's only if they'regood passwords. No matter how you slice it, passwords are annoying and on top of that, they're not even all that secure. Google knows that all too well, and it's pushing for the next big thing. A ring maybe. Like for your finger.

Google's been getting behind two-step verification for a while, and although that's more secure than a standard password, it's also more annoying. Hardly a perfect solution. In a paper to be published later this month inIEEE Security & Privacy Magazine, Google's President of Security Eric Grosse and Engineer Mayank Upadhyay are pitching alternatives like cryptographic card for your USB, or some kind of (presumably NFC) ring.

Google's got some software in the making that'd allow this kind of stuff to log you into a browser without involving any sort of software in the middle, just you and your browser. But even in the best possible future, it won't kill passwords completely. So long as your little key can be separated from you, you'll have to have a PIN or something, and the more conveniently short the PIN, the more important it is you don't loose that key. Still, it beats straight passwords and two-step verification annoyances. And the sooner the password can finally be laid to rest, the better.

The story of GOOGLE

Larry Page and Sergey Brin found the dominant, efficient, unbeatable web search giant company on the earth, in 1998, with an intention of putting together world’s information and making it easily accessible. There evolved a new definition for web search, which created a history. Their web search criteria revolutionized and ruled the Web. The base idea by which they created the search technology for Google mostly pivoted on a key point “Their technology analyzed the number of times a given website was linked to by other sites; assuming that the more links, the more relevant the site is and ranked the sites accordingly”. Today Google stands with pride with a yearly revenue of $6 billion and both Larry Page and Sergey Brin, the world’s richest technocrats. Recently the verb “to Google” made its place into Oxford English Dictionary.

Google achieved a path breaking success and was the most loved site of the customers through out the world, because of the fact that Google has a highly user friendly and simple interface. Other things that added upon for the success of Google were; paid links were clearly demarcated and identified, pop-windows or banner ads were not used and the homepage offered a clear logo and a single search box, where as the other search engines of that era were unbelievably saturated with sponsor messages. The major criteria that account to the huge success of Google other than technology are its site design and the mode of advertising.
Brin and Page met in computer science Ph.D. program at Stanford in the mid 90’s. Google started as a research project at Stanford University, created by Ph.D. candidates Larry Page and Sergey Brin when they were 24 years old and 23 years old respectively. Brin and Page first began with BackRub software and re-launched it under the name Google, chosen as a play on words of ‘googol’ a mathematical term meaning ‘one’ followed by 100 zeros. They used Stanford University website to host their program, with their website being google.stanford.edu.

Both friends together started working on the revolutionary search technology since 1996 and in 1998 they dropped out of Stanford and they started Google at a garage office, at Melano Park. Later in 2004, they took the company public.

Page ran Google as co-president along with Brin until 2001, while they hired Eric Schmidt as Chairman and CEO of Google. In January 2011, Google announced that Page would replace Schmidt as CEO in April the same year. Both Page and Brin earn an annual compensation of one dollar. On April 4, 2011, Page officially became the chief executive officer of Google, while Schmidt stepped down to become executive chairman.

Googleplex NYC, U.S.A

Tech journalists, Android journalists and Android enthusiasts thinking about moving to Mountainview California to be closer to the Googleplex, fuggedaboutit.  Google has closed a deal worth $1.8 billion dollars, purchasing an entire city block in New York City.

Although they are keeping their campus at 1600 Ampitheater Parkway in Mountainview California, Googlers on the east coast now have a new address, 111 8th Avenue New York, NY.  The collossal structure only fit for a king, or well Google, sits between 8th and 9th avenues and 15th and 16th strees, blockwide. It’s in the Chelsea neighborhood.

The Googleblock, as we’re going to call it, is 3 millon square feet. At the rate of Google’s growth they should have no problem filling the space.

Let us see how Google, started as a research project in a dorm room and then a cramped garage, has now become the largest internet company in the world.

On September 13, 1997, www.google.com was officially registered. One year later, Brin and Page incorporated Google as a private company, on September 7, 1998. It is an amazing fact that over 10,000 people viewed Google everyday at its very beginning stage, just by word of mouth advertising and continued to grow at the rate of 20% per month. In spite of many people using Google, Brin and Page did not have enough resources like computers to provide outstanding services to the customers. As they wanted everyone in the world to use Google search engine, they were desperately in need of capital, when the co-founder of Sun Andy Bechtolsheim wrote a check for $100,000 to an entity called Google Inc, which had not come into existence yet, in August 1998. In September, Google was incorporated in California, and Page and Brin opened a new bank account on the company’s name in which Andy’s cheque was deposited. They nearly bought 120 hard drives for a good deal, using all credit cards of their friends, and had a massive credit card debt. They felt some relief when private investments from Stanford came through.

The company later shifted from the dorm to a friend’s garage at 232 Santa Margarita, Menlo Park. In December 1998, Google was recognized as top 100 web sites of choice, as a search engine providing extremely relevant results, by Times magazine. Brin and Page soon came to know that they had hit something big. As some potential partners like Yahoo! showed little or no interest to license their technology, they decided to grow the company by themselves.

Soon they began approaching angel investors, venture capitalists and tried hard to raise money and had been successful, because most of them were convinced to invest for the great and worthy product they had in hand and everyone were using it. They managed to raise nearly $1million in all.

In 1999, Google finally moved into an office at 165 University Avenue in Palo Alto, California, with just eight employees. By this time, Google was answering over 500,000 searches each day. The same year, Google got its first commercial search customer, Red Hat, and managed to secure $25 million from two leading venture capital firms, Sequoia Capital and Kleiner Perkins, in Silicon Valley. As Google started hiring more number of people, Google’s headquarters was shifted to its current location 2400 E. Bayshore, Mountain View, California. Companies such as AOL/Netscape selected Google as its search engine, pushing Google’s users into millions.

In the year 2000, as many as 15 language versions of google.com were released (French, German, Italian, Swedish, Finnish, Spanish, Portuguese, Dutch, Norwegian, Danish, Chinese, Japanese and Korean). Google forged a partnership with Yahoo! and announced first billion-URL index to become world’s largest search engine.

In the year 2001, Google had a partnership with Universo Online (UOL), making Google the major search service for millions of Latin Americans and its index size increased to 3billion web documents. In 2002 the first Google’s hardware was released, Ad words were released on new cost-per-click basis, A set of API’s were released enabling developers to query more than 2 billion documents and program them in their favorite environment including Java, Perl and Visual Studio. A major partnership with AOL was announced to offer Google search, for more than 34mn customers using CompuServe, Netscape, and AOL.com. Google’s R&D team released Google labs a place to try beta technologies.

In the year 2003, Google acquired Pyra Labs, the creators of Blogger. Google launched, content-targeted advertising service, enabling publishers large and small to access Google‘s vast network of advertisers. Google Print was also launched. In 2004, the company moved to “Googleplex” at 1600 Amphitheatre Parkway in Mountain View, with a big campus to accommodate 800 plus employees. Orkut was launched to enter sphere of social networking. Google search index hit 6bn items, including 880 million images and 4.28 billion web pages. The company went public offering 19,605,052 shares on Wall Street, at $85 per share, on August 18, 2004. Google index reached nearly 8bn.

Likewise, over the consequent six years, Google continued to grow and expand its services. It introduced innovative advertising programs, improved its own benefits,went international and partnered with other corporate giants. Today, Google became the only website, available in more than 35 languages and is used by over 380 million people worldwide. There is no surprise to say that people of all age groups cannot live without Google.

Modem and Switches

One of the basic technical interview question:

Modem
A modem is adevice or program that enables acomputer to transmit dataover, for example, telephone or cable lines.There are different kinds of modems available in the market like LAN modem and Wifi Modems.

Switches

Switches are a fundamental part of most networks. Switches enable several users to send information over a network. Users can send the information at the same time and do not slow each other down. Just like routers allow different networks to communicate with each other, switches allow different nodes of a network to communicate directly with each other. A node is a network connection point, typically a computer. Switches allow the nodes to communicate in a smooth and efficient manner.

Routers

Routers are physical devices that join multiple wired or wireless networks together. Technically, a wired or wireless router is a Layer 3gateway, meaning that the wired/wireless router connects networks (as gateways do), and that the router operates at the network layer of the OSI model.

Basic difference between Router and Switch

A router is a more sophisticated network device than either a switch or a hub. Like hubs and switches, network routers are typically small, box-like pieces of equipment that multiple computers can connect to.
Each features a number of "ports" the front or back that provide the connection points for these computers, a connection for electric power, and a number of LED lights to display device status.
While routers, hubs and switches all share similar physical appearance, routers differ substantially in their inner working.

7 layers of Networking

    Interview questions in networks:

7 layers of Networking

Layer 1 PHYSICAL
Layer 2 DATA-LINK
Layer 3 NETWORK
Layer 4 TRANSPORT
Layer 5 SESSION
Layer 6 PRESENTATION
Layer 7 APPLICATION

The function of each layer:

•Physical Layer -The physical layer is concerned with transmitting raw bits over a communication channel though hubs, wires (cat5UTP), modems, network cards… basically anything that is physical to the network.
•THE DATA-LINK LAYER -The data link layer takes raw transmission and transform it into a line that appears free of transmission errors in the network layer
•THE NETWORK LAYER -The network layer is concerned with controlling the operation of the subnet. A ROUTER is used to determining how packets are routed from source to destination
•THE TRANSPORT LAYER -The transport layer “DIRECTS PACKETS”, splits it up into smaller units if need be, pass these to the network and ensure that the pieces are travelling in an orderly fashion.
•THE SESSION LAYER -The session layer allows different machines to establish sessions between themselves
•THE PRESENTATION LAYER -The Presentation Layer’s job is managing data restructures and converting from the representation used inside the computer to the network standard representation an visa versa
•THE APPLICATION LAYER -The Application layer contains a variety of protocols that are commonly required. Another Application layer function is file transfer. Different file systems have different file naming conventions, different ways of representing text lines, and so on

sizeof operator

We know that the sizeof(variable) returns the size of the variable and sizeof(pointer) returns the amount of memory that can be addressed  in bytes.

Try this program:

01	#include
02	#include

03	using namespace std;
04	void sz(int p[]){

05	cout<<"sz: "<<sizeof(p)<<"\n";
06	}

07	int main(){
08	int p[]={1,2,3,4};

09	cout<<"main: "<<sizeof(p)<<"\n";
10	sz(p);

11	cout<<"main: "<<sizeof(p)<<"\n";
12	cout<<"sizeof(p):"<<sizeof(p)<<"   sizeof(&p[0]):"<<sizeof(&p[0])<<"\n";

13	return 0;
14	}

Output you get will be:

1	main: 16
2	sz: 8

3	main: 16
4	sizeof(p):16   sizeof(&p[0]):8

int p[4];
we know that p points to the first element in the array so the sizeof(p) should return the size of the memory being addressed, and so p is same as &p[0] and so sizeof(p) and sizeof(&p[0]) should be same.But that is not the case, sizeof(p) gives the sizeof the array in bytes i.e sizeof(int)*4 in this case.