Estou de volta!!! Agora pretendo não ficar longo tempo sem fazer posts.

Neste post quero compartilhar este vídeo sobre o funcionamento de uma rede de computadores, inclusive a Internet que é a maior rede. Ele explica de forma muita legal o TCP/IP, proxy, firewall, etc.

Before you can change your IP you need some information. This information includes your IP range, subnet mask, default gateway, dhcp server, and dns servers.

1. Getting your IP range – Getting information about your IP range is not difficult, I recommend using Neo Trace on your own IP. But for my test just look at your IP address, say it’s 24.193.110.13 you can definitely use the IP’s found between 24.193.110.1 < [new IP] < 24.193.110.255, don’t use x.x.x.1 or x.x.x.255. To find your IP simply open a dos/command prompt window and type ipconfig at the prompt, look for “IP Address. . . . . . . . . . . . : x.x.x.x”.

2. Subnet Mask, Default Gateway, DHCP Server – These are very easy to find, just open a dos/command prompt window and type ‘ipconfig /all’ without the ‘ ‘. You should see something like this:

Windows IP Configuration:

Host Name . . . . . . . . . . . . . . : My Computer Name Here
Primary Dns Suffix . . . . . . . . . :
Node Type . . . . . . . . . . . . . . .: Unknown
IP Routing Enabled. . . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No

Ethernet adapter Local Area Connection:

Connection-specific DNS Suffix . . . . . . .: xxxx.xx.x
Description . . . . . . . . . . . . . . . . . . . . : NETGEAR FA310TX Fast Ethernet Adapter (NGRPCI)
Physical Address. . . . . . . . . . . . . . . . . : XX-XX-XX-XX-XX-XX
Dhcp Enabled. . . . . . . . . . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . . . . . . : Yes
IP Address. . . . . . . . . . . . . . . . . . . . . : 24.xxx.xxx.xx
Subnet Mask . . . . . . . . . . . . . . . . . . . .: 255.255.240.0
Default Gateway . . . . . . . . . . . . . . . . . : 24.xxx.xxx.x
DHCP Server . . . . . . . . . . . . . . . . . . . .: 24.xx.xxx.xx
DNS Servers . . . . . . . . . . . . . . . . . . . . : 24.xx.xxx.xxx
24.xx.xxx.xx
24.xx.xxx.xxx
Lease Obtained. . . . . . . . . . . . . . . . . . .:
Lease Expires . . . . . . . . . . . . . . . . . . . .:

This is all the information you will need for now, I suggest you either keep your dos/command prompt window open or copy & paste the information somewhere, to copy right click the window and select text and click once.

III. Changing your IP Address

To change your IP address first pick any IP you like out of your IP range and remember it or write it down. It is usualy a good idea to make sure the IP is dead (except for what we are going to do later on) so just ping it via “ping x.x.x.x” and if it times out then you can use it. Now go to My Computer, then Control Panel. In Control Panel select Network Connections and pick your active connection, probably Local Area Connection or your ISP name. Open that connection by double clicking on the icon in Network Connections, then select Properties under the General Tab. In the new window that pops up select Internet Protocol (TCP/IP) and click properties, it’s under the general tab. In this new window select the General tab and choose “Use the following IP address” and for the IP address enter the IP you would like to use (the one you picked from your subnet earlier) and for the Subnet Mask enter the subnet mask you got when your ran ipconfig /all, same goes for the Default Gateway. Now select “Use the following DNS server addresses” and enter the information you got earlier. Now just click OK. Test that it worked, try to refresh a website and if it works you know everything is okay and you are connected. To make sure the change worked type ipconfig again and the IP address should have changed to your new one.

IV. DDoS & DoS Protection

If your firewall shows that you are being DDoSed, this is usually when you are constantly getting attempted UDP connections several times a second from either the same IP address or multiple IP addresses (DDoS), you can protect your self by changing your IP address via the method I described above.

V. Web servers & Other Services

If you know someone on your IP range is running a web server and he or she has pissed you off or you just like messing around you can “steal” their IP address so any DNS going to that IP will show your site instead because you would be running a web server yourself.

To “steal” an IP is to basically use the changing IP address method above and picking an IP that someone that is running a web server has in use. Often you will be able to keep that IP at least for some time, other times you wont be able to use it so just keep trying until it works. You your self will need to have a web server on the same port with your message. You can do this with other services too. You can also DoS or DDoS the IP address you are trying to steal to kick him off the net, but I don’t recommend as its pretty illegal

Hi,

Here the placement for System Administrator – Abu Dhabi, UAE.

Position : System Administrator

No.Of Openings : 3

Experience : 3 years.

Qualification :

Location : Abu Dhabi, UAE.

Required Skill set :

• General understanding of Microsoft Windows Server OS and supporting systems including SMTP, Sites and directory object management.
• Knowledge of basic networking protocols such as TCP/IP, Kerberos and SNMP.
• Understanding of Server hardware and peripherals.
• Knowledge of Microsoft Windows based Operating Systems, networking best practices and troubleshooting techniques/
• Experience with Dell hardware and Dell Blade Servers.
• HP and/or Dell certification a plus.
• Hands on experience with a helpdesk ticket system. Remedy is preferred.
• Team oriented with a desire to succeed in a fast paced environment.
• Excellent customer service.

Would you be interested ?

Please send us your latest updated profile with contact nos.
current & expected salary details and joining time required toradha@kbsconsultants.com

You may also suggest this opening to your friends who may be interested.

Further Information:

KBS Consultants

Flat H,Kulothungan Apts,
No, 5 Natesan Road
Ashoknagar,
Chennai 600 083.
India
Phone: +91-44 2489 5341 / 2371 9622

Visit Our Sites:

International jobs: http://www.jobsearchworld.com/
SAP ERP Jobs : http://www.jobsvista.com/
Core Engineering Jobs : http://www.gotachance.com/
Technology Jobs : http://www.kbsconsultants.com/
India Jobs :http://www.kbsconsultants.org.in

This position is an Application Administrator to support operations within our client’s department. This position has a critical role in delivering our services to clients and ensuring successful ongoing operation of our applications and services. It services a highly interactive software development build/release process as well as a rich operational environment with many interrelated applications/database services. The candidate should be self-motivated, detail oriented, adaptable to change and must work well in a flexible team environment with developers, QA, operations staff, system administrators and managers.

RESPONSIBILITIES:

Application and database support

• Provide on-going database administration in both back-end and front-end with application infrastructure support for our client’s administration systems, including the deployment of new applications.
• Review the physical design of existing databases for optimal database structures, database performance tuning, security, database backup/recovery strategy, implementing high-availability, and pro-active and reactive performance analysis, monitoring, troubleshooting and resolution of issues, capacity planning, monitoring data growth and system utilization, trend analysis and predicting future database resource requirements.
• Install web-base applications from ground up to full-ballooned implementation and support, including configuration at Unix/Linux/Windows system level, back-end integration with database, front-end integration with user-interface, final delivery to users to fulfill users’ requirement and on-going maintenance.
• Take the lead in ensuring that application and web services are configured and tuned according to application needs; provide troubleshooting as needed.
• Work with System Administrators to ensure test and production boxes conform to the software application configuration needs.
• Support the department-wide infrastructure application for database management, system monitoring and notification, job scheduling, deployment, provision and patching automation, application topology and service level management for campus-wide system performance.

Build/release activities

• Manage the build, tagging and release processes for a number of interdependent Java web applications and background processes in the QA and production environments. Ensure the build and release process is scalable and repeatable.
• Work with the development team to ensure efficient and understandable build procedures are adhered to and conform to a standard process for configuration and release management
• Develop and maintain tools that automate the building of software releases for an Agile-based development process. This is one of continuous integration, where the automated build process can be run many times a day if necessary.
• Work with and support the QA team to ensure automated test suites run as part of the continuous integration build process.

REQUIREMENT FOR SKILL AND COMPETENCIES:

• Expert hands-on with shell scripts, other scripting languages, preferably Perl, and tool automations
• Minimum 2 years database administration experience in Oracle and 3 years Application administration experience in Unix/Linux infrastructure environments is required.
• Hands-on experience of Oracle databases 10g for 24/7 database operations and tool automation in installation, configuration, backup/recovery, startup/shutdown, data refresh, and application integrations.
• Experience with OEM/Grid Control is highly desired.
• Knowledge and understanding of large scale ERP implementation and support like Oracle Financial and PeopleSoft systems.
• Expert knowledge of Apache and Tomcat, and other web/application servers such as JBoss
• Strong Unix and system administration skills with basic network and security knowledge
• Strong experience and ability in web applications deployment, configuration and integration from both OpenSource and Commercial based systems with or without sophisticated vendor support.
• Java/J2EE based programs
• Java/servlet/JSP based web applications
• Experience with Subversion, PVCS or similar source code repository
• Experience with Maven and familiarity with automated build processes
• Experience with the Agile development methodology and concepts of extreme programming and continuous integration
• Understanding of the layers/tiers of web applications and the communication protocol between the tiers with networking protocols (TCP/IP, HTTP, SSL, DNS, FTP, etc.)
• Ability to multi-task and work in a team environment is critical and should have excellent communication skills in both verbal and written forms.
• Ability to manage multiple competing priorities and work under pressure in high stress situations
• Excellent communication skills in both verbal and written
• Ability to work under pressure and to deliver results in a complex and dynamic operational environment

Qualifications

Minimum 5 years as an IT professional in build/release and application/database administration, plus one or more of the following areas: IT infrastructure operations 24/7, systems analysis and design, or application development.

Education
Bachelors Degree in Computer Science, Engineering or related field or equivalent experience

If you are interested, please send your resume to tsotelo@mindsource.com.

Have the Printer’s IP ready before you proceed:

1. Click Start, Settings, Printers
2. Click Add Printer
3. From Add Printer Wizard, click Next
4. Click Local Printer, (uncheck Automatically detect!) click Next
5. Click Create a new port, click select type to Standard TCP/IP Port. Click Next
6. Click Next on printer wizard
7. type in the IP address. (leave port name alone). Click Next
8. Click Finish
9. Select the manufacturer and printer model, click Next
10. (it might ask you if you want to keep existing driver, YES). click Next
11. Change the printer name if you want to. Click Next
12. Click Next on printer sharing. (Do not share)
13. Click Yes or no for a test page, click Next
14. Click Finish.. DONE

In this current age of converging systems an airport is probably one of the most information communications technology (ICT) intensive users. All the systems are ICT based running on the TCP/IP platform. All the systems are integrated to form a whole while affording the individual systems the benefit of individuality via Virtual Private Networks (VPNs) while sharing a common communications system. To examine the anatomy of this system let us follow a passenger through the system and have a peek at what happens behind the scenes… (more)

berikut perbandingan antara 3 protocol

Model Arcitecture TCP/IP

diantara contoh service yang menggunakan TCP -UDP :

Untuk mengecek apakah modem tellabs beroperasi normal atau tidak, kita bisa melihat dari indikator lampunya (hanya berlaku pada modem tellabs yang memiliki led indicator 103,104,105,106 & 109),

1. Jika semua lampu menyala maka modem tellabs OK
2. Jika 104 & 109 mati -> kemungkinan besar problem pada ISP
3. Jika 103 & 105 mati -> kemungkinan problem ada pada router atau kabel, langkah yang bisa diambil :

• modem mungkin belum tersambung dengan router atau kabelnya kendor ->   Cek kabel serial, coba cabut colok.

• Interface serial di router dalam keadaan shutdown -> Hidupkan interface serial dengan masuk melalui remote atau console

• Kabel serial salah colok di interface modem -> cek dengan standbye engineer dan juga provider selaku penyedia modem

Espero no aburrir ni confundir a nadie con las dos entradas anteriores sobre puertos abiertos en windows. Para abreviar un poco hay una herramienta llamada tcpview descargable del link http://live.sysinternals.com/ solo esta herramienta o todo el conjunto de utilidades, muy básicas pero muy prácticas de http://download.sysinternals.com/Files/SysinternalsSuite.zip.

es entretenido el ir viendo como se van viendo y moviendo las conexiones y como van modificando su estado bajo el protocolo tcp/ip de desconexión o conexión con otro servicio.

Ya sería un motivo de preocupación el no saber o reconocer donde está conectado el ordenador o bajo que programa se encuentra conectado al exterior.

conexiones a ordenador remoto al puerto 80 o http significa simplemente que seguramente hay un navegador abierto y este el motivo. Tambien podría ser debido a alguna actualización del sistema operativo o antivirus. Aquí comenzará el análisis y el aprendizaje.

If you’re reading this article, it’s likely that you spend a fair amount of time online. However, considering how much of an influence the Internet has in our daily lives, how many of us actually know the story of how it got its start?

Here’s a brief history of the Internet, including important dates, people, projects, sites, and other information that should give you at least a partial picture of what this thing we call the Internet really is, and where it came from.

While the complete history of the Internet could easily fill a few books, this article should familiarize you with key milestones and events related to the growth and evolution of the Internet between 1969 to 2009.

1969: Arpanet

Arpanet was the first real network to run on packet switching technology (new at the time). On the October 29, 1969, computers at Stanford and UCLA connected for the first time. In effect, they were the first hosts on what would one day become the Internet.

The first message sent across the network was supposed to be “Login”, but reportedly, the link between the two colleges crashed on the letter “g”.

1969: Unix

Another major milestone during the 60’s was the inception of Unix: the operating system whose design heavily influenced that of Linux and FreeBSD (the operating systems most popular in today’s web servers/web hosting services).

1970: Arpanet network

An Arpanet network was established between Harvard, MIT, and BBN (the company that created the “interface message processor” computers used to connect to the network) in 1970.

1971: Email

Email was first developed in 1971 by Ray Tomlinson, who also made the decision to use the “@” symbol to separate the user name from the computer name (which later on became the domain name).

1971: Project Gutenberg and eBooks

One of the most impressive developments of 1971 was the start of Project Gutenberg. Project Gutenberg, for those unfamiliar with the site, is a global effort to make books and documents in the public domain available electronically–for free–in a variety of eBook and electronic formats.

It began when Michael Hart gained access to a large block of computing time and came to the realization that the future of computers wasn’t in computing itself, but in the storage, retrieval and searching of information that, at the time, was only contained in libraries. He manually typed (no OCR at the time) the “Declaration of Independence” and launched Project Gutenberg to make information contained in books widely available in electronic form. In effect, this was the birth of the eBook.

1972: CYCLADES

France began its own Arpanet-like project in 1972, called CYCLADES. While Cyclades was eventually shut down, it did pioneer a key idea: the host computer should be responsible for data transmission rather than the network itself.

1973: The first trans-Atlantic connection and the popularity of emailing

Arpanet made its first trans-Atlantic connection in 1973, with the University College of London. During the same year, email accounted for 75% of all Arpanet network activity.

1974: The beginning of TCP/IP

1974 was a breakthrough year. A proposal was published to link Arpa-like networks together into a so-called “inter-network”, which would have no central control and would work around a transmission control protocol (which eventually became TCP/IP).

1975: The email client

With the popularity of emailing, the first modern email program was developed by John Vittal, a programmer at the University of Southern California in 1975. The biggest technological advance this program (called MSG) made was the addition of “Reply” and “Forward” functionality.

1977: The PC modem

1977 was a big year for the development of the Internet as we know it today. It’s the year the first PC modem, developed by Dennis Hayes and Dale Heatherington, was introduced and initially sold to computer hobbyists.

1978: The Bulletin Board System (BBS)

The first bulletin board system (BBS) was developed during a blizzard in Chicago in 1978.

1978: Spam is born

1978 is also the year that brought the first unsolicited commercial email message (later known as spam), sent out to 600 California Arpanet users by Gary Thuerk.

1979: MUD – The earliest form of multiplayer games

The precursor to World of Warcraft and Second Life was developed in 1979, and was called MUD (short for MultiUser Dungeon). MUDs were entirely text-based virtual worlds, combining elements of role-playing games, interactive, fiction, and online chat.

1979: Usenet

1979 also ushered into the scene: Usenet, created by two graduate students. Usenet was an internet-based discussion system, allowing people from around the globe to converse about the same topics by posting public messages categorized by newsgroups.

1980: ENQUIRE software

The European Organization for Nuclear Research (better known as CERN) launched ENQUIRE (written by Tim Berners-Lee), a hypertext program that allowed scientists at the particle physics lab to keep track of people, software, and projects using hypertext (hyperlinks).

1982: The first emoticon

While many people credit Kevin MacKenzie with the invention of the emoticon in 1979, it was Scott Fahlman in 1982 who proposed using after a joke, rather than the original -) proposed by MacKenzie. The modern emoticon was born.

1983: Arpanet computers switch over to TCP/IP

January 1, 1983 was the deadline for Arpanet computers to switch over to the TCP/IP protocols developed by Vinton Cerf. A few hundred computers were affected by the switch. The name server was also developed in ‘83.

1984: Domain Name System (DNS)

The domain name system was created in 1984 along with the first Domain Name Servers (DNS). The domain name system was important in that it made addresses on the Internet more human-friendly compared to its numerical IP address counterparts. DNS servers allowed Internet users to type in an easy-to-remember domain name and then converted it to the IP address automatically.

1985: Virtual communities

1985 brought the development of The WELL (short for Whole Earth ‘Lectronic Link), one of the oldest virtual communities still in operation. It was developed by Stewart Brand and Larry Brilliant in February of ‘85. It started out as a community of the readers and writers of the Whole Earth Review and was an open but “remarkably literate and uninhibited intellectual gathering”. Wired Magazine once called The Well “The most influential online community in the world.“

1986: Protocol wars

The so-called Protocol wars began in 1986. European countries at that time were pursuing the Open Systems Interconnection (OSI), while the United States was using the Internet/Arpanet protocol, which eventually won out.

1987: The Internet grows

By 1987, there were nearly 30,000 hosts on the Internet. The original Arpanet protocol had been limited to 1,000 hosts, but the adoption of the TCP/IP standard made larger numbers of hosts possible.

1988: IRC – Internet Relay Chat

Also in 1988, Internet Relay Chat (IRC) was first deployed, paving the way for real-time chat and the instant messaging programs we use today.

1988: First major malicious internet-based attack

One of the first major Internet worms was released in 1988. Referred to as “The Morris Worm”, it was written by Robert Tappan Morris and caused major interruptions across large parts of the Internet.

1989: AOL is launched

When Apple pulled out of the AppleLink program in 1989, the project was renamed and America Online was born. AOL, still in existence today, later on made the Internet popular amongst the average internet users.

1989: The proposal for the World Wide Web

1989 also brought about the proposal for the World Wide Web, written by Tim Berners-Lee. It was originally published in the March issue of MacWorld, and then redistributed in May 1990. It was written to persuade CERN that a global hypertext system was in CERN’s best interest. It was originally called “Mesh”; the term “World Wide Web” was coined while Berners-Lee was writing the code in 1990.

1990: First commercial dial-up ISP

1990 also brought about the first commercial dial-up Internet provider, The World. The same year, Arpanet ceased to exist.

1990: World Wide Web protocols finished

The code for the World Wide Web was written by Tim Berners-Lee, based on his proposal from the year before, along with the standards for HTML, HTTP, and URLs.

1991: First web page created

1991 brought some major innovations to the world of the Internet. The first web page was created and, much like the first email explained what email was, its purpose was to explain what the World Wide Web was.

1991: First content-based search protocol

Also in the same year, the first search protocol that examined file contents instead of just file names was launched, called Gopher.

1991: MP3 becomes a standard

Also, the MP3 file format was accepted as a standard in 1991. MP3 files, being highly compressed, later become a popular file format to share songs and entire albums via the internet.

1991: The first webcam

One of the more interesting developments of this era, though, was the first webcam. It was deployed at a Cambridge University computer lab, and its sole purpose was to monitor a particular coffee maker so that lab users could avoid wasted trips to an empty coffee pot.

1993: Mosaic – first graphical web browser for the general public

The first widely downloaded Internet browser, Mosaic, was released in 1993. While Mosaic wasn’t the first web browser, it is considered the first browser to make the Internet easily accessible to non-techies.

1993: Governments join in on the fun

In 1993, both the White House and the United Nations came online, marking the beginning of the .gov and .org domain names.

1994: Netscape Navigator

Mosaic’s first big competitor, Netscape Navigator, was released the year following (1994).

1995: Commercialization of the internet

1995 is often considered the first year the web became commercialized. While there were commercial enterprises online prior to ‘95, there were a few key developments that happened that year. First, SSL (Secure Sockets Layer) encryption was developed by Netscape, making it safer to conduct financial transactions (like credit card payments) online.

In addition, two major online businesses got their start the same year. The first sale on “Echo Bay” was made that year. Echo Bay later became eBay. Amazon.com also started in 1995, though it didn’t turn a profit for six years, until 2001.

1995: Geocities, the Vatican goes online, and JavaScript

Other major developments that year included the launch of Geocities (which officially closed down on October 26, 2009).

The Vatican also went online for the first time.

Java and JavaScript (originally called LiveScript by its creator, Brendan Eich, and deployed as part of the Netscape Navigator browser – see comments for explanation) was first introduced to the public in 1995. ActiveX was launched by Microsoft the following year.

1996: First web-based (webmail) service

In 1996, HoTMaiL (the capitalized letters are an homage to HTML), the first webmail service, was launched.

1997: The term “weblog” is coined

While the first blogs had been around for a few years in one form or another, 1997 was the first year the term “weblog” was used.

1998: First new story to be broken online instead of traditional media

In 1998, the first major news story to be broken online was the Bill Clinton/Monica Lewinsky scandal (also referred to as “Monicagate” among other nicknames), which was posted on The Drudge Report after Newsweek killed the story.

1998: Google!

Google went live in 1998, revolutionizing the way in which people find information online.

1998: Internet-based file-sharing gets its roots

In 1998 as well, Napster launched, opening up the gates to mainstream file-sharing of audio files over the internet.

1999: SETI@home project

1999 is the year when one of the more interesting projects ever brought online: the SETI@home project, launched. The project has created the equivalent of a giant supercomputer by harnessing the computing power of more than 3 million computers worldwide, using their processors whenever the screensaver comes on, indicating that the computer is idle. The program analyzes radio telescope data to look for signs of extraterrestrial intelligence.

2000: The bubble bursts

2000 was the year of the dotcom collapse, resulting in huge losses for legions of investors. Hundreds of companies closed, some of which had never turned a profit for their investors. The NASDAQ, which listed a large number of tech companies affected by the bubble, peaked at over 5,000, then lost 10% of its value in a single day, and finally hit bottom in October of 2002.

2001: Wikipedia is launched

With the dotcom collapse still going strong, Wikipedia launched in 2001, one of the websites that paved the way for collective web content generation/social media.

2003: VoIP goes mainstream

In 2003: Skype is released to the public, giving a user-friendly interface to Voice over IP calling.

2003: MySpace becomes the most popular social network

Also in 2003, MySpace opens up its doors. It later grew to be the most popular social network at one time (thought it has since been overtaken by Facebook).

2003: CAN-SPAM Act puts a lid on unsolicited emails

Another major advance in 2003 was the signing of the Controlling the Assault of Non-Solicited Pornography and Marketing Act of 2003, better known as the CAN-SPAM Act.

2004: Web 2.0

Though coined in 1999 by Darcy DiNucci, the term “Web 2.0″, referring to websites and Rich Internet Applications (RIA) that are highly interactive and user-driven became popular around 2004. During the first Web 2.0 conference, John Batelle and Tim O’Reilly described the concept of “the Web as a Platform“: software applications built to take advantage of internet connectivity, moving away from the desktop (which has downsides such as operating system dependency and lack of interoperability).

2004: Social Media and Digg

The term “social media”, believed to be first used by Chris Sharpley, was coined in the same year that “Web 2.0″ became a mainstream concept. Social media–sites and web applications that allow its users to create and share content and to connect with one another–started around this period.

Digg, a social news site, launched on November of 2004, paving the way for sites such as Reddit, Mixx, and Yahoo! Buzz. Digg revolutionized traditional means of generating and finding web content, democratically promoting news and web links that are reviewed and voted on by a community.

2004: “The” Facebook open to college students

Facebook launched in 2004, though at the time it was only open to college students and was called “The Facebook”; later on, “The” was dropped from the name, though the URL http://www.thefacebook.com still works.

2005: YouTube – streaming video for the masses

YouTube launched in 2005, bringing free online video hosting and sharing to the masses.

2006: Twitter gets twittering

Twitter launched in 2006. It was originally going to be called twittr (inspired by Flickr); the first Twitter message was “just setting up my twttr”.

2007: Major move to place TV shows online

Hulu was first launched in 2007, a joint venture between ABC, NBC, and Fox to make popular TV shows available to watch online.

2007: The iPhone and the Mobile Web

The biggest innovation of 2007 was almost certainly the iPhone, which was almost wholly responsible for renewed interest in mobile web applications and design.

2008: “Internet Election”

The first “Internet election” took place in 2008 with the U.S. Presidential election. It was the first year that national candidates took full advantage of all the Internet had to offer. Hillary Clinton jumped on board early with YouTube campaign videos. Virtually every candidate had a Facebook page or a Twitter feed, or both.

Ron Paul set a new fundraising record by raising $4.3 million in a single day through online donations, and then beat his own record only weeks later by raising $4.4 million in a single day.

The 2008 elections placed the Internet squarely at the forefront of politics and campaigning, a trend that is unlikely to change any time in the near future.

2009: ICANN policy changes

2009 brought about one of the biggest changes to come to the Internet in a long time when the U.S. relaxed its control over ICANN, the official naming body of the Internet (they’re the organization in charge of registering domain names).

The Future?

Where is the future of the Internet headed? Share your opinions in the comments section.

original post From  Sixrevisions.com

Há uma certa tendência de muitos acreditarem que não existem vírus para sistemas operacionais abertos, como o GNU/Linux. Isso não é uma verdade absoluta. Na verdade, existem cerca de 1000 vírus conhecidos vírus para GNU/Linux (contra cerca de 6 milhões – e subindo – deles para os sistemas janelas), incluídos aí os rootkits, worms e scripts para invasão.

E isso é motivo para alarmes? Na verdade, não. Uma questão relevante sobre a existência de malwares é o impacto que tais programas têm no sistema infectado. Os vírus são desenvolvidos para explorar falhas de segurança dos sistemas. Descobrir falhas de segurança em sistemas proprietários é um pouco mais difícil do que em sistemas abertos, porque, no primeiro, o cracker precisa fazer uma engenharia reversa para “recuperar” o código fonte. No segundo, o código fonte está disponível para qualquer pessoa.

Auditoria de código.

O que parece uma desvantagem para o sistema aberto, na verdade, é uma absurda vantagem. Enquanto que, nos sistemas fechados, o cracker faz a engenharia reversa, ou outros métodos, descobre as falhas e cria maneiras de explorá-las para, somente depois, o vírus ser descoberto pelos pesquisadores e empresas de segurança, e medidas sejam tomadas para, primeiro, contornar (antivírus), e depois corrigir a falha (correções e atualizações), nos sistemas abertos, o código é auditado constantemente por milhares de desenvolvedores voluntários ao redor do mundo. Isso permite que as falhas sejam descobertas e corrigidas com mais rapidez. O mesmo trabalho que um cracker teria de fazer para descobri-las, já é feito diariamente por muitas pessoas. Além de descobrir um código defeituoso, ele teria de procurar se esse defeito já não está documentado, pois se estiver, a correção estará na próxima atualização, com certeza. Nos sistemas fechados, a velocidade de pesquisa dos códigos e de correção é absurdamente maior, o que significa que, mesmo que a falha seja descoberta, não significa que será corrigida imediatamente. Isso expõe o sistema a ataques que a explorem.

Isso também significa que, nos sistemas abertos, os crackers estão no mesmo passo dos desenvolvedores, ou um passo atrás, mas estão sempre um ou dois passos à frente nos sistemas proprietários.

Atualizações e correções.

As atualizações de segurança em sistemas abertos é feita da mesma forma que em sistemas fechados, ou seja, através do download de correções, ou de versões novas do software com defeito. Ocorre que, nos sistemas proprietários, temos uma fragmentação das fontes de software, ou seja, são vários fornecedores diferentes, trabalhando de maneira independente, nem sempre coordenada e, por vezes, concorrentes. Isso causa problemas do tipo ocorrido recentemente, em que uma correção de segurança do Internet Explorer, lançada pela M$, abriu brechas de segurança no Navegador Mozilla Firefox para janelas. Além disso, as correções são feitas independentemente, ou seja, cada um é responsável pelo seu pedaço: o antivírus, o sistema operacional, o pacote de escritório, o navegador, o cliente de email, o pacote gráfico, os jogos, o firewall, etc.

Nos sistemas abertos, isso é bastante minimizado, já que todas as atualizações são disponibilizadas nos repositórios oficiais. Também são automáticas, mas estão todas agrupadas e podem ser feitas de uma vez. Há coordenação entre as equipes de desenvolvimento através do responsável pela distribuição. Programas “não oficiais” podem ser instalados e ter sua atualização feita em separado, mas são poucos os casos, já que cada distribuição já inclui tudo, ou quase tudo, que é necessário para a maior parte das pessoas.

Exposição a ataques.

Há um mito que diz que apenas existem mais vírus para janelas porque o GNU/Linux é bem menos utilizado. Ou seja, o janelas é mais visado.

Isso é uma meia verdade. Se fosse possível comprovar essa afirmação, poderíamos supor seria proporcional a disponibilidade de malwares para os dois sistemas. Recentemente, foi publicada uma matéria sobre a taxa de penetração de cada um dos sistemas operacionais. O janelas (em todas as suas versões) ficou com aproximadamente 90%, O GNU/Linux com 1%, e o Sistema da Maçã com cerca de 5%. Seria, portanto, lógico supor que dos milhões de vírus conhecidos, a proporção fosse semelhante, mas não é o que acontece. Os vírus para GNU/Linux respondem por cerca de 0,16% do total de vírus conhecidos, número semelhante aos do Sistema da Maçã, sistema proprietário cujo desenvolvimento foi baseado em Unix.

Dos vírus conhecidos para Sistema da Maçã e GNU/Linux, não se comprovou que algum deles causasse transtornos semelhantes aos causados pelos que atingem o janelas. Além disso, a forma de considerar a segurança em sistemas Unix-like, como o GNU/Linux e o Sistema da Maçã, é completamente diferente e bem mais aprimorada. Numa instalação padrão, a exposição a ataques desses sistemas é consideravelmente menor. O que significa que se você pegar um CD e instalar uma distribuição qualquer do GNU/Linux em um computador conectado diretamente à Internet, a possibilidade de invasão é quase nula. O mesmo computador com uma instalação padrão do sistema janelas XP tem um tempo médio e resistência de 90 segundos. Ou seja, se você formatar a sua máquina e instalar o janelas XP nela, se ela estiver na Internet, você tem, em média, 90 segundos para instalar todas as atualizações de segurança, antivírus, antispyware, firewall, etc., o que é virtualmente impossível para qualquer “usuário comum”.

O janelas, ao contrário dos sistemas Unix-like, não foi originalmente concebido para trabalhar em rede. A demanda pela conectividade, na época do DOS+janelas 3.1, fez com que a M$ lançasse a versão 3.11 do janelas, com recursos de rede. A empresa tentou impor seu protocolo NetBeui como padrão para as redes locais, mas não conseguiu porque o TCP/IP já estava bem consolidado, e era utilizado na Internet restrita da época. Durante algum tempo, as redes locais não eram conectadas à Internet e trafegavam NetBeui. Quando começou a aparecer a necessidade de conectar essas redes à Internet, elas começaram a trafegar ambos os protocolos e, por fim, o NetBeui foi abandonado. As versões do janelas seguintes, não mudaram o conceito original. Hoje o janelas é altamente conectável, mas, como originalmente a segurança do sistema foi pensada para máquinas isoladas, quando muito conectadas em redes locais, por uma questão de compatibilidade com as versões anteriores e pelo custo de desenvolvimento, o conceito se propagou até os dias de hoje.

Custos de desenvolvimento e estratégia de marketing.

O custo de desenvolvimento de um sistema operacional completo pode chegar à casa de alguns bilhões de dólares. Por mais rica que uma empresa seja, um investimento desse tamanho é algo impraticável. Empresas como Petrobras, por exemplo, quando constroem uma refinaria de 2 ou 3 bilhões de dólares, invariavelmente procuram se associar a outras empresas e buscar financiamento de longo prazo em bancos, para o empreendimento. Vejam bem, uma refinaria pode ficar pronta em cerca de 2 ou 3 anos e tem um prazo de algumas dezenas de anos para pagar o financiamento e amortizar o investimento, além de dar lucro aos acionistas.

O que podemos dizer de um sistema operacional? Com a velocidade imposta para que uma versão de um sistema operacional proprietário seja substituído, seria necessário investir muitas centenas de milhões de dólares por ano no desenvolvimento de sistemas completamente novos para resolver o problema de segurança. Mas, a cada versão da família janelas, vemos as mesmas alegações de que o sistema novo é mais seguro que o antigo, fatos “comprovados” por pesquisas de cunho duvidoso e declarações de “especialistas” dos quais nunca se ouviu falar. O fato é que nunca se cria um sistema novo. Ela apenas se recicla códigos dos sistemas antigos, remodelando o velho para “criar o novo”, oferecendo um visual agradável para que o marketing atinja seus objetivos. É necessário que o ciclo seja curto para garantir os lucros altos. Portanto, não há tempo nem disponibilidade orçamentária, ou de financiamento, para a criação de um sistema novo, sem vícios herdados dos anteriores. Logo, o fato do janelas não ser um sistema seguro não se deve a uma questão de filosofia de código, mas a uma questão econômica. Se, mesmo com um sistema ruim, mantém-se a hegemonia do mercado, não há motivos econômicos para melhorar substancialmente o sistema, já que há quem o compre e o use sem grandes esforços de marketing. Além disso, existe uma “indústria da segurança” por trás disso. Além da M$, empresas como McAfee, Symantec, Trend Micro, entre outras, ganham fortunas oferecendo soluções paliativas para os problemas estruturais do janelas. Não espere que o janelas 7 seja muito melhor em termos de segurança do que seus antecessores, pois um sistema inseguro, mas hegemônico, é tudo o que a M$ e dezenas de empresas de segurança precisam para manter os acionistas felizes, e os usuários iludidos, mas igualmente felizes.

Os custos de desenvolvimento do kernel do Linux foi estimado em cerca de 614 milhões de dólares, e o de uma distribuição GNU/Linux típica em 1,2 bilhões de dólares. Esse capital não é investido por uma única empresa, mas diluído entre milhares (talvez milhões) de empresas e pessoas comuns ao redor do mundo, que contribuem com um pouco para que o sistema final chegue ao que se espera. Por isso é possível oferecer um sistema seguro a um preço irrisório. Não existe a preocupação com um ciclo de vida curto para garantir os lucros. Na verdade, a preocupação é exatamente oposta: ter um sistema estável e seguro para que se possa oferecer serviços constantes aos clientes. Sempre que uma versão nova do janelas é lançada, há uma demanda geral por novos treinamentos, novos equipamentos, novas “expertises“. No GNU/Linux, o ciclo é muito maior. Isso significa que quem usa uma versão 7.04 do Ubuntu, por exemplo, também usará uma versão 9.10, sem grandes dificuldades, porque na essência o sistema é o mesmo, mas as inovações se traduzem em mais compatibilidade, mais funcionalidades, mais segurança. Também não há grandes preocupações com a atualização do parque de máquinas porque a versão 9.10 rodará na maior parte das máquinas que rodavam a versão 7.04, por exemplo. Finalmente, não haverá a necessidade de uma urgente atualização do conhecimento dos técnicos de suporte, já que em essência, as mudanças são focadas na inovação, ou seja, não há mudança no conceito.

Aqui podemos ver uma situação curiosa: No sistema proprietário, não há mudança num conceito ruim que é perpetuado para que o “produto” continue a gerar lucros com mudanças “cosméticas”. Isso é bom para a empresa desenvolvedora, para as empresas de software incluídas no ecossistema. Não é tão bom para os técnicos porque precisam investir constantemente em treinamento, nem para os usuários que além do treinamento devem arcar com os custos do modelo (licenças de software diversas, treinamento constante, prejuízos decorrentes da insegurança do sistema, etc.). No sistema livre, o conceito originalmente bom, não tem a necessidade de ser modificado em profundidade, o que justifica mudanças que focam na inovação. Isso é bom para o ecossistema produtivo como um todo, já que diminui os custos tanto de desenvolvimento como o de treinamento de técnicos e usuários.

Como você pode observar, no sistema proprietário, a carga econômica fica com o consumidor final, bem como o ônus das deficiências do sistema. No sistema aberto, a carga é diluída entre todos e não há grandes ônus para nenhum dos envolvidos.

A questão comportamental.

Há uma tendência dos técnicos em afirmar que nenhum sistema é seguro, e que boa parte da segurança depende de quem o utiliza. Isso pode ser ou não uma verdade. Eu discordo de que isso seja uma verdade absoluta.

Partindo de uma instalação padrão, ou seja, uma que até seu sobrinho nerd poderia fazer, num sistema GNU/Linux é difícil para um “usuário padrão”, mesmo com comportamentos de risco, tornar o sistema vulnerável, a ponto de ser comparado aos sistemas janelas. Para fazer isso, ele teria de ter certos conhecimentos técnicos. Seria necessário habilitar o login automático do usuário root (o que por si só já é uma proeza), abrir todas as portas TCP e UDP fechadas por padrão (e para isso teria de instalar pacotes que não são instalados e/ou configurados por padrão), desabilitar o pedido de senha para ações consideradas “administrativas”, e/ou alterar os privilégios de usuário comum. Isso é bem mais do que um “usuário padrão” faria no janelas. No janelas, em uma instalação padrão, o administrador do sistema é quase que sugerido como usuário padrão. Um usuário não precisa se esforçar muito para abrir as poucas defesas existentes. Isso, aliado à insegurança inerente e aos comportamentos de risco (clicar em links suspeitos de email, entrar em sites de reputação duvidosa, instalar programas piratas de origem duvidosa, utilizar programas de downloads como bitorrent ou semelhantes, desabilitar a proteção por senhas do sistema para alterações no registro, não instalar atualizações, não saber como utilizar um antivirus, não usar o firewall, senhas pequenas e óbvias, etc.), tornam o janelas um verdadeiro problema para que o usa e uma ótima oportunidade para quem quer invadi-lo.

A falácia dos antivírus.

A maior ilusão de um usuário do janelas é pensar que um antivírus o salvará das pragas da Internet. Para se beneficiar da proteção oferecida pelos antivírus, são necessárias três condições adicionais:

• Conhecimento técnico para sua correta configuração, atualização e utilização (o que muito poucos detém);
• Utilização de softwares complementares como firewall e antispyware (o que também exige conhecimento técnico);
• Comportamentos seguros na utilização da Internet (o que exige treinamento e capacitação).

Se qualquer um dos três requisitos não for atendido, todo o resto será comprometido, ou seja, as várias centenas de reais gastos com toda essa parafernália será, literalmente, inútil.

As empresas de segurança há anos fingem que são capazes de oferecer proteção para seus clientes, mas têm absoluta certeza de que isso é uma batalha perdida, portanto, a única razão para continuarem a oferecer “soluções de segurança” é a existência de uma massa enorme de pessoas que as compram acreditando que elas tornarão seu sistema seguro. They don’t give a damn, they just want the money.

Recentemente, Eva Chen, uma das fundadoras da Trend Micro, concedeu uma entrevista onde afirma que os crackers estão na dianteira e que a indústria de antivírus é uma piada (de mal gosto). Portanto, se nem eles acreditam que poderão ganhar o jogo, porque você, que é o elo mais fraco, se arriscaria a bancá-lo?

Conclusão.

Existem vírus para Linux? Sim, existem mas, na prática, são completamente irrelevantes, pois não só é difícil de encontrá-los, como seu impacto é irrisório.

Se você não acredita que é possível existir um sistema seguro que dificulta ao máximo a infecção por vírus, o uso não autorizado da sua máquina, seja por crackers, seja por “empresas idôneas”, e que tira das suas costas grande parte da responsabilidade sobre a segurança dos seus dados e arquivos, deveria experimentar o GNU/Linux ou outro sistema aberto, como o FreeBSD. Não se trata de militância ideológica a favor de sistemas livres. Trata-se de resguardar o que é seu, seu patrimônio, sua privacidade e sua liberdade. É uma questão prática, não filosófica.

Porque pagar, ou usar ilegalmente um sistema que, notoriamente, é problemático e o expõe a riscos, os quais você nem mesmo dá conta da existência, nem tem condições de se proteger, se é possível ter um sistema seguro e gratuito?

Por que pagar por softwares “tapa buraco”, como os antivírus, que tapam o sol como uma peneira, se é possível ter um sistema que não necessita desses paliativos?

Pense bem sobre isso. E depois considere usar uma distribuição GNU/Linux.

lme shared a Perl script that feeds text files to the #twatch through the Matrix Orbital-compatible TCP/IP server.

The project SVN has several example scripts for the #twatch, if you’ve got something interesting we’d like to host a copy.

Thanks for the tip! Via the forum.