Internet Firewalls Can Prevent Browsing and File Sharing

A firewall is software or hardware that creates a protective barrier between your computer and potentially damaging content on the Internet. It helps guard your computer against malicious users and against many computer viruses and worms.A firewall is software or hardware that creates a protective barrier between your computer and potentially damaging content on the Internet. It helps guard your computer against malicious users and against many computer viruses and worms.

Important If you set up a firewall to help protect computer ports that are connected to the Internet, we do not recommend that you open these ports because they can be exposed to other computers on the Internet. Additionally, specific computers cannot be granted access to the open ports.

The following ports are associated with file sharing and server message block (SMB) communications:

* Microsoft file sharing SMB: User Datagram Protocol (UDP) ports from 135 through 139 and Transmission Control Protocol (TCP) ports from 135 through 139.
* Direct-hosted SMB traffic without a network basic input/output system (NetBIOS): port 445 (TCP and UPD).

Symptoms:

After you enable an Internet firewall, you may not be able to search, or "browse," for other computers on your home or office network, and you may not be able to share files with other computers on your home or office network. For example, when you enable the Internet Connection Firewall (ICF) feature in Microsoft Windows XP, you find that you cannot browse your network by using My Network Places. Also, if you use the net view \\computername command to view shares on a computer on your home or office network, you may receive the following error message:
System error 6118 has occurred. The list of servers for this workgroup is not currently available.


Cause:

This behavior may occur if you enable a firewall on the network connection that you use for your home or office network. By default, a firewall closes the ports that are used for file and print sharing to prevent Internet computers from connecting to file and print shares on your computer.

Resolution:

To resolve this behavior, use a firewall only for network connections that you use to connect directly to the Internet. For example, use a firewall on a single computer that is connected to the Internet directly through a cable modem, a DSL modem, or a dial-up modem. If you use the same network connection to connect to both the Internet and a home or office network, use a router or firewall that prevents Internet computers from connecting to the shared resources on the home or office computers.

Do not use a firewall on network connections that you use to connect to your home or office network unless the firewall can be configured to open ports only for your home or office network. If you connect to the Internet by using your home or office network, a firewall can be used only on the computer or the other device, such as a router, that provides the connection to the Internet. For example, if you connect to the Internet through a network that you manage, and that network uses connection sharing to provide Internet access to multiple computers, you can install or enable a firewall only on the shared Internet connection. If you connect to the Internet through a network that you do not manage, verify that your network administrator is using a firewall.

The Internet's Owners

So who actually owns the Internet? There are two answers to this question:

1. Nobody
2. Lots of people

If you think of the Internet as a unified, single entity, then no one owns it. There are organizations that determine the Internet's structure and how it works, but they don't have any ownership over the Internet itself. No government can lay claim to owning the Internet, nor can any company. The Internet is like the telephone system - no one owns the whole thing.

From another point of view, thousands of people and organizations own the Internet. The Internet consists of lots of different bits and pieces, each of which has an owner. Some of these owners can control the quality and level of access you have to the Internet. They might not own the entire system, but they can impact your Internet experience.

The physical network that carries Internet traffic between different computer systems is the Internet backbone. In the early days of the Internet, ARPANET served as the system's backbone. Today, several large corporations provide the routers and cable that make up the Internet backbone. These companies are upstream Internet Service Providers (ISPs). That means that anyone who wants to access the Internet must ultimately work with these companies, which include:

* UUNET
* Level 3
* Verizon
* AT&T
* Qwest
* Sprint
* IBM

Then you have all the smaller ISPs. Many individual consumers and businesses subscribe to ISPs that aren't part of the Internet backbone. These ISPs negotiate with the upstream ISPs for Internet access. Cable and DSL companies are examples of smaller ISPs. Such companies are concerned with what the industry calls the last mile -- the distance between the end consumer and Internet connectivity.

Within the backbone are Internet Exchange Points (IXPs), which are physical connections between networks that allow data exchanges. For example, while Sprint, Verizon and AT&T provide part of the Internet backbone's infrastructure, the three networks aren't intertwined. They connect together at an IXP. Several companies and non-profit organizations administer IXPs.

The individual computer networks that make up the Internet can have owners. Every ISP has its own network. Several nations' governments oversee computer networks. Many companies have local area networks (LANs) that link to the Internet. Each of these networks is both a part of the Internet and its own separate entity. Depending on local laws, the owners of these networks can control the level of access users have to the Internet.

You might consider yourself to be an owner of the Internet. Do you own a device that you use to connect to the Internet? If so, that means the device you own becomes part of the enormous inter-networked system. You are the proud owner of part of the Internet - it's just a very small part.

How to Protect Your Computer from Viruses

You can protect yourself against viruses with a few simple steps:

• If you are truly worried about traditional (as opposed to e-mail) viruses, you should be running a more secure operating system like UNIX. You never hear about viruses on these operating systems because the security features keep viruses (and unwanted human visitors) away from your hard disk.
• If you are using an unsecured operating system, then buying virus protection software is a nice safeguard.
• If you simply avoid programs from unknown sources (like the Internet), and instead stick with commercial software purchased on CDs, you eliminate almost all of the risk from traditional viruses.
• You should make sure that Macro Virus Protection is enabled in all Microsoft applications, and you should NEVER run macros in a document unless you know what they do. There is seldom a good reason to add macros to a document, so avoiding all macros is a great policy.
• You should never double-click on an e-mail attachment that contains an executable. Attachments that come in as Word files (.DOC), spreadsheets (.XLS), images (.GIF), etc., are data files and they can do no damage (noting the macro virus problem in Word and Excel documents mentioned above). However, some viruses can now come in through .JPG graphic file attachments. A file with an extension like EXE, COM or VBS is an executable, and an executable can do any sort of damage it wants. Once you run it, you have given it permission to do anything on your machine. The only defense is never to run executables that arrive via e-mail.
  

How Computer Viruses Work

Strange as it may sound, the computer virus is something of an Information Age marvel. On one hand, viruses show us how vulnerable we are - a properly engineered virus can have a devastating effect, disrupting productivity and doing billions of dollars in damages. On the other hand, they show us how sophisticated and interconnected human beings have become.

For example, experts estimate that the Mydoom worm infected approximately a quarter-million computers in a single day in January 2004. Back in March 1999, the Melissa virus was so powerful that it forced Microsoft and a number of other very large companies to completely turn off their e-mail systems until the virus could be contained. The ILOVEYOU virus in 2000 had a similarly devastating effect. In January 2007, a worm called Storm appeared -- by October, experts believed up to 50 million computers were infected. That's pretty impressive when you consider that many viruses are incredibly simple.

When you listen to the news, you hear about many different forms of electronic infection. The most common are:

• Viruses - A virus is a small piece of software that piggybacks on real programs. For example, a virus might attach itself to a program such as a spreadsheet program. Each time the spreadsheet program runs, the virus runs, too, and it has the chance to reproduce (by attaching to other programs) or wreak havoc.

• E-mail viruses - An e-mail virus travels as an attachment to e-mail messages, and usually replicates itself by automatically mailing itself to dozens of people in the victim's e-mail address book. Some e-mail viruses don't even require a double-click -- they launch when you view the infected message in the preview pane of your e-mail software.
  

• Trojan horses - A Trojan horse is simply a computer program. The program claims to do one thing (it may claim to be a game) but instead does damage when you run it (it may erase your hard disk). Trojan horses have no way to replicate automatically.

• Worms - A worm is a small piece of software that uses computer networks and security holes to replicate itself. A copy of the worm scans the network for another machine that has a specific security hole. It copies itself to the new machine using the security hole, and then starts replicating from there, as well.

Digital Tools Let Doctors See Patients via Internet

When Robyn Broomell was pregnant a few years ago, she needed advice from a specialist at the University of Maryland Medical Center because she is a diabetic.

But Broomell, 35, of Rising Sun, never set foot in the specialist's Baltimore office. Instead, she met him several times by video conference while she was at an Elkton hospital, saving her the trip down Interstate 95.

"At first, I was kind of leery" of long-distance medical advice, she said. "I thought it was kind of an odd thing. But it was very convenient, and I could get used to convenience. It takes me 45 minutes to an hour to drive to Baltimore, and I didn't have to do that."

Broomell was an early beneficiary of "telehealth," in which medical professionals using digital tools and the Web can cut the waiting time for care from days or weeks to minutes.

Thanks to factors including a looming physician shortage, the health care reform debate and the increasing willingness of insurance companies to pay for the practice, telehealth is on the verge of becoming routine.

In the near future you could be connected by video to a specialist dozens or hundreds of miles away. Consider something as mundane as a skin rash. If your primary care doctor thinks she needs outside expertise, she can use digital diagnostic tools to generate high-resolution images of the rash and beam them to a dermatologist in another office for rapid diagnosis.

"More and more companies are seeing the benefits of telehealth," said Greg Billings, senior director at the nonprofit Center for Telehealth and E-Health Law in Washington. "If that doctor looking at that skin rash didn't diagnose it as skin cancer until later, the cost of treatment of that skin cancer is going to be a heck of a lot more."

Universities, technology companies and hospital systems, including the University of Maryland, have been experimenting with telehealth since the 1990s. A major insurance provider - UnitedHealthcare of Minnesota - recently announced a national push to persuade its network of professionals, including thousands here in Maryland, to adopt telehealth for their patients.

Remote consultation and diagnosis are ways for medicine to become more efficient even as physicians and other health professionals are increasingly in short supply, policy experts say. For patients living away from advanced hospitals in urban areas, they add, it's potentially lifesaving.

Telehealth systems can screen patients for diabetes, eye disease, kidney problems, nerve damage, vascular disease and complicated pregnancies. The technology is available and relatively inexpensive. It's the regulatory hurdles that present the challenge, experts say.

Because of licensing restrictions, specialists might have trouble treating and prescribing medicine for patients they are examining electronically across state lines. Also, only a handful of states require insurers to cover telehealth care - and Maryland isn't one of them.

The Internet Advantage

Internet is a system with which we can know the global conditions within no time. Not only the information on internet about the whole world are available but it has revolutionized the communication techniques. This new invention has given a large projection to communication.
Here is the advantages/benefits of internet :

1. It provides instant communication—to almost anywhere:

If something happens in Washington, or Baghdad, or Hobart or even Tierra del Fuego or the South Pole, it can be instantly communicated around the globe with a few keystrokes. Digital media preparation and presentation can flash photos online in seconds.

This ability to spread news quickly can have massive effects—good and bad. A 14-year-old in Hong Kong stitched together a web page that looked like the site of a local newspaper. In it he said the city was going to be quarantined over the SARS situation. As a result, stock prices fell on the local exchange, some panic buying ensued and the government sent out approximately six million emails to combat the rumor.

On the other hand, as the Year 2000 dawned in the Pacific, word flashed around the globe that things were going well in each time zone as local computer clocks rolled over to the new millennium. There was no need to panic. Now that’s a good thing.

As illustrated by the teenager in Hong Kong, a good thing can go bad, but having access to information quickly and from authoritative sources (the Sydney Morning Herald, let’s say, versus a less-known web site), can stop rumours in their tracks, while keeping a world hungry for information well fed.

A corollary to this is now the ability for time-shifting communication. The editor of this magazine is about 10 time zones away from the writer of this article. While there are periods of the day when we both are at our desks, there is a far greater period of time in which we are each alone on duty. Using email lets me communicate at my pace, while the editor can then respond at his. Once I’m back at my desk (or he at his), we can open and answer the other’s emails. Even with the time difference, this is easier and quicker than any other method of communication—far faster than the old-world habit of “snail mail,” known as the post to many of us!

2. It affords wider commercial opportunity:

Factories and merchants now connect directly, cutting shipping time and saving money in many ways. But, even more important, the benefits of the Internet are there for small and remote business communities.
For example, take the case of Mata Ortiz, a small and remote village in the Mexican state of Chihuahua. Twenty-five years ago, it was on the verge of becoming a ghost town. Business had dried up, the railway had stopped running and poverty was rampant.

But Juan Quezada, a local man, kept thinking about the shards of pottery he found in hiking around the area. Inspired by tales of the great artisans of his area of years gone, he began to duplicate their potting techniques. Practise and patience yielded success; he taught others in the community to make the beautiful, intricate designs that have become collector’s items worldwide.

In the past couple of years, however, the Quezada family and others in Mata Ortiz have used the Internet, specifically an auction site called eBay, to market their wares. Collectors can bid and buy with the click of a mouse, export companies now make the trek the railway stopped making, and the families of Mata Ortiz no longer worry about poverty, instead using a Toyota ute to give their tired burros a break.

The Quezadas and their neighbours credit the Internet with enhancing their success and their industry. And this is not a unique situation: other people in other places are starting successful businesses online to market artworks and other crafts to a global audience.

Having the ability to market what was once sold only locally to a global audience can only help world trade and engender international understanding. Mail order has been a staple worldwide since the 19th-century beginnings of international mail; now, however, the commerce can be far more interactive and immediate.

3. It gives greater access to more knowledge:

Recently I was in a bookstore looking at new almanacs. I was ready to buy one until it occurred to me, just about any piece of information I might need is but a few keystrokes away—fresher and faster than any book—on the Internet. The Internet, through search engines such as Google, and services like RefDesk.com, Britannica.com (and dozens of others), I can access information as quickly as I desire.

Though some might consider such a treatment slothful (“In my day, we had to walk half an hour to the library and we were glad to do so!”), for those who are pressed for time, stressed for resources or don’t have access to the books and ephemera found in larger cities, the Internet is a heaven-sent blessing of inestimable magnitude.

The practical outworking of such knowledge access may never be fully known. But it’s been well documented that increased access to health information is making patients better prepared for consultations with their often-harried doctor, surgeon or medical specialist. When a patient (or family member) walks in with an understanding of a given ailment, time is saved and healing can often begin more quickly. Sometimes, even, the visit itself is avoided.

In business, you are only as good as the latest data. Having a global “network of networks”—which the Internet is—as a resource allows many a business person (myself included) to double-check things before a presentation, or even while a meeting is in progress. The Internet, clearly, provides many benefits to those seeking fast access to data and information, whether for business, education or personal use.

It is an especially valuable service to shut-ins, who, with some coaching, can virtually walk the globe, visiting all manner of places and browsing a huge range of information right from their home.

4. It opens the door to other cultures:

You can censor or block postal mail. Radio stations can be jammed. And while some countries—notably China—try to block web sites, the Internet can get into many, many more places than one might imagine.

That’s helped people find music from unknown or hard-to-locate artists within seconds; to read writings of authors and poets from other cultures; and it has enabled religions to share their faith and point of view across the world.

While fanatic Muslims threaten jihad on Middle Eastern sites, neo-Nazis threaten everyone on US sites. But in Norway, the email exchange a person has with an evangelical pastor in New Jersey leads to their conversion. In isolated Bangladesh and Congo, missionaries get official instructions from their headquarters in seconds, and for a few cents, as opposed to the uncertainties, weeks and dollars of a courier service or regular mail.