Computer Security 101: Lesson 1

[tonybradley]

Since one of our compatriots already shared Lesson 1 of my Computer Security 101 series I thought I would officially add the lessons to the Tutorials forum here on AO. However, due to copyright and legal restrictions I can't simply cut and paste the whole thing. I am going to post a big chunk of each lesson and then link back to the original article on About.com for those who wish to read the entire lesson.

In order to better secure your home computer or home network it helps if you have some basic knowledge of how it all works so you can understand what exactly you are securing and why. This will be the first in a 10-part series to help provide an overview of the terms and technology used and some of the tips, tricks, tools and techniques you can use to make sure your computer is secure.

To begin with, I want to provide some understanding of what these terms are so that when you read about the latest malicious code spreading through the Internet and how it gets into and infects your computer you will be able to decipher the techie terms and determine if this affects you or your computer and what steps you can or should take to prevent it. For Part 1 of this series we will cover Hosts, DNS, ISP’s and Backbone.

The term “host” can be confusing because it has multiple meanings in the computer world. It is used to describe a computer or server that provides web pages. In this context it is said that the computer is “hosting” the web site. Host is also used to describe the companies that allow people to share their server hardware and Internet connection to share these as a service rather than every company or individual having to buy all their own equipment.

A “host” in the context of computers on the Internet is defined as any computer that has a live connection with the Internet. All computers on the Internet are peers to one another. They can all act as servers or as clients. You can run a web site on your computer just as easily as you can use your computer to view web sites from other computers. The Internet is nothing more than a global network of hosts communicating back and forth. Looked at in this way, all computers, or hosts, on the Internet are equal.

Each host has a unique address similar to the way street addressing works. It would not work to simply address a letter to Joe Smith. You have to also provide the street address- for example 1234 Main Street. However, there may be more than one 1234 Main Street in the world, so you must also provide the city- Anytown. Maybe there is a Joe Smith on 1234 Main Street in Anytown in more than one state- so you have to add that to the address as well. In this way, the postal system can work backward to get the mail to right destination. First they get it to the right state, then to the right city, then to the right delivery person for 1234 Main Street and finally to Joe Smith.

On the Internet, this is called your IP (Internet protocol) address. The IP address is made up of four blocks of three numbers between 0 and 255. Different ranges of IP addresses are owned by different companies or ISP’s (Internet service providers). By deciphering the IP address it can be funneled to the right host. First it goes to the owner of that range of addresses and can then be filtered down to the specific address its intended for.

I might name my computer “My Computer”, but there is no way for me to know how many other people named their computer “My Computer” so it would not work to try to send communications to “My Computer” any more than addressing a letter simply to “Joe Smith” would get delivered properly. With millions of hosts on the Internet it is virtually impossible for users to remember the addresses of each web site or host they want to communicate with though, so a system was created to let users access sites using names that are easier to recall.

Computer Security 101: Lesson 1

[noODle]

Well I just finished reading all four.
They are nice, readable and informative.
Can we still expect the remaining 6 ?

Nice job tony !

[tonybradley]

Thanks.

I have been writing about 1 a week or so. I will post the other 6 as I complete them.

[shadow_dancer]

Nice job tony,
The basic lesson about computer security in first lesson, i love reading it tony.
Keep on it tony, and hope u can give us another.

[tonybradley]

Most of the people on AO could probably do this quiz in their sleep, but the audience that the Computer Security 101 series is designed for may benefit from it.

I just added a quiz for Lesson 1 and will be adding quizzes for the other lessons throughout the week. I will hopefully be finally posting Lesson 7 in the next week or two as well.

Now that I have discovered the quiz tools I will add other quizzes on more difficult topics to the site too outside of the Computer Security 101 series.

Here is a link to the quiz: Computer Security 101 - Lesson 1 Quiz

[d00dz Attackin]

Nice tut, and quiz sounds "kool" am going to take it, and see if am reading and not thinking off in space. Hhehe .

Cya

[souleman]

Originally posted here by tonybradley
Most of the people on AO could probably do this quiz in their sleep,

PLEASE... tell me you are kidding right? Either that or you haven't been reading very many posts.

[anjali]

Tony the articles are truly amazing....

Seldom see articles which build the subject from absolute basics....

An excellent piece of info for newbies.....

May be experienced people may skip major part of current writeup..
I am sure the value addition will happen as you go further.....

All the best buddy.. and keep up the great job......

Regards

Kalp

[tonybradley]

PLEASE... tell me you are kidding right? Either that or you haven't been reading very many posts.

Point taken.

There are almost always more Guests than Members online anyway. And, there are hundreds, maybe thousands, of Members who rarely or never post. Many of those could be old or defunct or duplicate accounts, but it still points out the fact that there are maybe 50 or so people who post on a regular basis out of hundreds of Members and that a greater number of Guests come and go everyday.

Actually, I think there are plenty of members- and an equal or greater number of guests- who could benefit from reading the Computer Security 101 series and taking the quizzes. They are written for an audience assumed to be coming in with essentially no tech knowledge and I try to explain things in English rather than "techie" or use analogies that help relate the "techie" back to English as much as possible.

So, the quizzes and the information may be too easy for the CCNA's and CISSP's out there, but for the intended audience I think they do the trick.

[Opiumsniper]

Phenominal Tony, you explained basically Cisco Semester 1 in your 10 lessons; what Cisco took 15 elongated ones and 400 webpages to do.